SUBMERGED BATTLEFIELD
SURVEY MANUAL
Community Approaches
Current Methodologies
Battlefield Analysis
Incorporating stakeholders
and community members
into battlefield research
projects
An introduction to survey
techniques for investigating
submerged battlefields
The value of military terrain
analysis to understanding
and preserving conflict sites
Table of
CONTENTS
#3 Introduction
#4 Research Potential of Submerged American Battlefields
#5 Community Stewardship and Stakeholders
#6 Submerged Battlefield Study
#8 Defining Submerged Battlefield Boundaries and Features
#14 Submerged Archeological Fieldwork
#16 Lowtech and Hightech Technology
#22 Recording Features and Record Keeping
#24 Final Products
#26 Photogrammetry
#28 Conclusion
#29 Glossary
#30 References Cited and Additional Resources
#31 Submerged Battlefield-Related Organizations
Grant Agreement No. GA-2287-17-015
American Battlefield Protection Program
Submerged Battlefield Survey Manual
Jennifer F. McKinnon, Madeline Roth, Toni L. Carrell
Ships of Exploration and Discovery Research, Inc.
2020
This material is based upon work assisted by a grant from the Department of the Interior, National Park Service. Any opinions, findings, conclusions,
or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of the Interior.
FRONT COVER: SHERMAN TANK, SAIPAN. IMAGE COURTESY OF SHIPS OF DISCOVERY
INSET: (LEFT) WWII BATTLEFIELD OF KISKA, AK. IMAGE COURTESY OF PROJECT RECOVER; (RIGHT) WWII JAPANESE BOMBER. IMAGE
COURTESY OF EAST CAROLINA UNIVERSITY
#2
INTRODUCTION
The archeology of battlefields is a relatively recent area of study.
Beginning in the 1980s, the subfield adapted terrestrial and submerged
research methodologies to record and analyze historic battle sites.
Closely related to conflict archeology, the study of battlefields
addresses both material remains of the conflict and the landscapes
that facilitated combat. Because battlefields vary in environment,
historic context, and scale, there is no standardized approach
to battlefield survey. Every project has different parameters and
will require a specialized recording strategy for investigation and
preservation.
Similar to many archeological resources, American battlefield sites face
destruction from development, changing environmental conditions,
and human actions. Submerged battlefields are threatened by
looting and treasure hunting in addition to biological and chemical
deterioration. While environmental factors may be outside the control
of those interested in site preservation, community appreciation for
historic battlefields is crucial for their protection. The necessary first
step to any long-term preservation is battlefield identification and
documentation.
The study of submerged battlefields is guided by current battlefield
research methodologies, including analysis of historic documents,
terrain, and artifacts. The major difference between terrestrial and
submerged battlefield archeology is the environmental site context;
working in submerged environments requires the use of different
technologies to access sites and interpret terrain features. The aim of
this manual is to present the steps necessary for identifying, recording,
and preserving submerged battlefields and is designed for use by
SHPOs, THPOs, and ABPP grantees.
#3
Research Potential of
SUBMERGED AMERICAN BATTLEFIELDS
ACTION BETWEEN MERRIMAC AND MONITOR, J. ROGERS 1862. IMAGE FROM NAVAL HISTORY AND HERITAGE COMMAND
Differing environments and military strategies create a signature on the seabed
that requires a unique approach to how battlefields are studied and preserved.
America’s waterways are
important features of our
historic battlefields. They
were used as transportation
to battles and were the
platforms on and in which
battles occurred. From the
Revolutionary War to World
War II, battles took place on or
around the Atlantic and Pacific
Oceans, the Gulf of Mexico,
and countless lakes, rivers, and
estuaries.
mind, but researching and
understanding portions of the
battlefield that took place on
the water, and might still be
submerged, completes the
story.
Some battles took place
completely on water, such
as the Battle of Lake Erie
between the American and
British Royal Navies, while
others took place on and
under the water, such as the
engagement between USS
The submerged portion of
a battlefield can tell us as
Housatonic and submarine HL
much about the battle as
Hunley. Still others have both
areas on land. This is why
land and water components,
it is important to look at a
such as the WWII amphibious
battlefield holistically and
invasion of the Pacific island of
consider the full landscape and Saipan or the 1776 American
seascape. It is easy to ignore
retreat at Arnold’s Bay on Lake
what is underwater because
Champlain in Vermont. These
it is out of sight and out of
different environments and
#4
associated military strategies
and tactics create a signature
on the seabed that requires a
unique approach to how they
are studied and preserved.
Depending on many
environmental and cultural
factors, submerged battlefields
can range from nearly intact to
highly disturbed. Additionally,
communities might be very
aware of their existence,
having passed the history
down through generations, or
completely unaware. Even if a
community is unaware, they
still should be considered a
stakeholder in the preservation
of that battlefield and every
effort should be made to
engage them early in the
process of documentation and
in preservation strategies.
Community
STEWARDSHIP AND STAKEHOLDERS
The key to protecting battlefields is community.
Community comes in many forms and involves
multiple stakeholders. Potential stakeholders
can include veterans and veteran families,
non-combatant civilians and their ancestors,
landowners, local governments, and tourists. Each
stakeholder might relate to the battle differently.
For example, descendants of soldiers may feel a
sense of pride while non-combatant civilians, to
whom the battle happened and disrupted their
lives, may feel a sense of sadness and resentment.
It is important to consider all stakeholders when
attempting to identify, research, and interpret
historic battlefields.
Engaging community and stakeholders can take
the form of pre-planning public meetings with
input at the beginning of a project, regular contact
and updates, even involvement in the archeology
and historical research. Stakeholders may act as
reviewers of reports or publications. These steps
provide communities the opportunity to develop
a sense of stewardship and ownership, which is
important in protecting battlefields long term.
Because submerged battlefields are underwater
it is important to consider that they might not be
accessible to those who do not have the personal
capital or physical ability to dive. Finding ways to
incorporate more than just divers in the study of
submerged battlefields should be a key part of
any project.
ELDER ESCOLASTICA BORJA TUDELA CABRERA SHARING WWII MEMORIES. IMAGE COURTESY OF SHIPS OF
DISCOVERY
Community comes in many
forms and involves multiple
stakeholders
ABPP Submerged Battlefield Grants
The National Park Service (NPS) American Battlefield Protection Program (ABPP) was created
to assist individuals, groups, organizations, and governments with researching, evaluating,
interpreting, and protecting historic American battlefields. Battlefield sites hold national
significance and are preserved so that present and future generations can “better understand
the connection between military conflicts and important social and political changes” (ABPP
2019). Since 1991, ABPP and partner organizations have surveyed more than 650 American
battlefields covering 16 wars. Today, ABPP continues to allocate grants for the study and
preservation of historic American battlefields, both submerged and terrestrial. The ABPP
provided funding for the development of this manual because of the unique circumstances
inherent in the study of submerged battlefields. For more information, visit www.nps.gov/abpp.
#5
SUBMERGED BATTLEFIELD SURVEY
An historic landscape approach can be used to interpret and record battlefields.
Terrain features influenced military strategy and tactics, which in turn shaped the
material record of the battle. While significant terrain features may no longer exist
today, it is necessary to a) identify them in the historic record to determine historic
significance, and b) ground truth the same features to determine modern cultural
significance—assessing which features have been lost and which features remain.
Battlefield assessment and survey follows five steps—creation of a research
design, preliminary battle research, definition of battlefield boundary and
terrain features, fieldwork, and reporting. Each step is discussed with necessary
modifications for submerged battlefields.
RESEARCH DESIGN
Written research designs
are a necessity before any
archeological fieldwork can
take place. A research design
outlines project significance,
aims, methods, equipment,
and the necessary steps to
meet project goals. While the
research design addresses
historical background and
relevant methodologies for
fieldwork and reporting,
it also indicates that the
researcher is aware of all local
and Federal guidelines for
archeological investigations
that may be applicable to the
project. Finally, it identifies
the relevant stakeholders
and necessary steps for
community engagement.
The research design is used
in any subsequent permitting
processes and becomes a
necessary first step in planning
a successful battlefield project.
HISTORICAL
BACKGROUND
accessing eyewitness accounts
and records.
Historical research is critical
to any battlefield evaluation.
While the archeological
record contains physical
remnants of the battle,
historical sources can provide
valuable contextual clues
about the significance of
battlefield remains. Prior to
any in-field work, researchers
should begin by compiling
battle accounts, including
both primary and secondary
sources. It is recommended
that researchers begin by
collecting the secondary
sources created after the initial
event. These materials can
provide an overview of major
events and place battles within
their larger social, political,
and economic contexts.
Furthermore, these sources
use primary documents and
may have suggestions for
Materials that are
contemporary to the battle are
considered primary sources,
as are those published later by
eyewitnesses. These primary
documents can include
anything from personal journal
entries and oral histories
to official military records,
photographs, and films. The
scope of primary sources
will vary depending on the
author’s role in the battle
and the intended audience.
Diaries of sailors, for example,
may solely reflect their
experience on the frontlines,
while paperwork filed by their
superior officers discusses
large scale operations. Both
these accounts are valuable to
understanding the progression
of battle but will vary in degree
of detail, terminology, and
tone. When evaluating any
#6
This “fog of war” brought on by adrenaline, fear, or even confusion, can blur or
distort details in the historic record.
JURISDICTION
primary source, it is important
for the researcher to be
aware of any possible biases,
shortcomings, and the author’s
intent.
One caveat to working with
historic records is that they can
be riddled with inaccuracies
and conflicting statements.
Combat participants often only
experienced their immediate
surroundings, and so may
share secondhand information
in written statements that
contradict other sources.
Furthermore, battle participants
were subjected to human
emotions during the conflict,
which can muddle accounts
recorded after the fact. This
“fog of war” brought on by
adrenaline, fear, or even
confusion, can blur or distort
details in the historic record. For
that reason, researchers should
carefully evaluate written
histories and note discrepancies
and possible sources of error.
Submerged battlefields and associated artifacts fall under
various jurisdictions based on geographic location and
resources investigated. While there are some general
considerations listed below, it is important to research all
relevant governing bodies and associated legislation to
secure proper permitting and permission for investigation.
General Jurisdictional Considerations: Inland lakes, rivers,
and coastal waters (extending 3 miles offshore or 6 leagues
for Texas, Florida, and Puerto Rico’s coastlines bordering
the Gulf of Mexico) fall under state jurisdiction and require
SHPO/THPO consultation. Bottomlands extending from 3
to 200 miles offshore fall under Federal jurisdiction as do
any submerged lands protected by Federal entities. These
are subject to national legislation along with navigable
waterways under the jurisdiction of the U.S. Army Corps of
Engineers.
The Sunken Military Craft Act (SMCA) of 2004 preserves
and protects from unauthorized disturbance all sunken
military craft that are owned by the U.S. government, as
well as foreign sunken military craft that lie within U.S.
waters. If any submerged resources are identified, or likely
to be identified as military craft, the U.S. Department of
the Navy should be contacted for the proper archeological
permitting. For more information, visit:
https://www.history.navy.mil/research/underwaterarchaeology/policy-and-resource-management/sunkenmilitary-craft-act.html.
CSS NASHVILLE SIDESCAN SONAR IMAGE. COURTESY OF GEORGIA HISTORIC PRESERVATION DIVISION
Defining
SUBMERGED BATTLEFIELD BOUNDARIES AND FEATURES
One aim of battlefield
investigation is to document
the battlefield boundary and
physical features of the event.
This requires delineating the
battlefield boundary, or the
area in which the battle took
place. To do this geographic
coordinates that are historically
defensible and supported by
archeological and/or historical
evidence are required. Within
this boundary, researchers may
also address two additional
areas: the core area, or area
where the most significant
combat occurred, and the
Potential National Register
Boundary, which encompasses
areas of the battlefield and
areas that retain historic
integrity. If made prior to
fieldwork, designation of the
battlefield boundary will aid in
delineating the archeological
survey area. It may be difficult,
however, to establish the
boundary in areas of subtle or
seemingly featureless terrain.
Following project work, the
boundary also can be updated
as necessary.
during field survey. Also note
if these features appear in
multiple sources, because
this indicates they were
significant to the sequence
of events for multiple parties.
Some archeologists use
KOCOA terrain analysis to
determine defining features.
Below are several suggested
approaches for identifying
defining features using
historic accounts. These
methodologies are all currently
used in submerged battlefield
archeology. The best
methodological approach for
any project, however, will be
guided by the aims and goals
of the research.
IPB AND KOCOA
historic accounts to identify
defining features in the
landscape. The interpretation
of these features is based
on their significance to the
course of battle and ability to
influence events. The value
of KOCOA analyses is that
the approach specifically
identifies both cultural and
natural terrain features and
challenges the researcher
to think about the influence
of terrain on combat. While
traditionally used with
terrestrial analyses, the KOCOA
terrain feature groupings have
been expanded to include
naval and aerial battlefield
parameters (Babits et al. 2011;
Roth and McKinnon 2018). An
overview of KOCOA attributes
is presented in Table 1.
Intelligence Preparation
of the Battlefield (IPB) is a
methodology used by the
U.S. armed forces to analyze
enemy, terrain, and effect
of weather on a specific
geographic area. The aims
of IPB are to evaluate enemy
capabilities, vulnerabilities,
and potential courses of action
(Stanley 1986:24). Part of the
Similar to the battlefield
IPB process is terrain analysis,
boundary, defining features
are terrain features designated characterized by the acronym
in historic accounts (including OCOKA, which stands for
Observation and fields of
maps) that influenced the
fire, Cover and concealment,
battle. These features can be
human-made (e.g. vessels, aids Obstacles, Key terrain, and
to navigation, and observation Avenues of approach and
withdrawal.
posts) or naturally occurring,
such as channels and fringing
reefs. While analyzing historic Archeologists have adapted
OCOKA, rewritten as KOCOA
source material, keep a list of
with Key Terrain first, for
defining features that have
battlefield study by using
the potential to be relocated
#8
IMAGE COURTESY OF GEORGIA HISTORIC
PRESERVATION DIVISION
Table 1. KOCOA Terrain Features and Parameters
Attribute
Definition
Naval Parameters
(Babits et al. 2011)
Aerial Parameters
(Roth and McKinnon 2018)
Examples
Key Terrain
Ground that
must be
controlled to
accomplish the
mission.
Navigable waterways
offer access to
terrestrial targets.
Areas of land or
buildings which sit
above the water
greatly enhance
visibility.
Enemy-held
areas, forces, and
infrastructure
are target areas.
Landing zones, drop
zones, and refueling
are key terrain for
aerial combat.
High ground with
good observation
and clear fields of
fire, transportation
choke point,
junction, landing/
loading and
refueling area,
navigable waterway,
the weather gauge.
Observation
and Fields of
Fire (FF)
The ability to
see friendly and
enemy forces.
FF are areas
that weapons
cover/can fire on
efficiently.
Coastal defenses,
ships, and vessels on
the water are highvisibility structures.
Vessel armament
defines field of fire
but will fluctuate
with wind, tides,
channel obstructions,
topographic
obstructions, and
enemy defenses.
Areas of
engagement and
surveillance are
larger. Aircraft and
ground forces need
large clearings for
visibility. Maximum
firing range of
artillery and antiaircraft defenses.
High ground,
sloping ground,
entrenched
positions, ship
superstructure,
observation towers,
radar, some
terrestrial coastal
defenses.
Cover and
Concealment
Protection from
enemy fire,
observation, and
surveillance.
Defenders have
foreknowledge of
navigable waters
and create defenses
to protect/obstruct
waterways. Vessels
provide cover to their
occupants.
Cloud cover and
time of day impact
visibility as well as
enemy surveillance
equipment.
Topography and
vegetation limits
aerial visibility.
Ditches, buildings,
walls, forests,
ravines, reverse
slopes, radar, cloud
cover, mist, fog,
night, vessels.
Obstacles
Natural or
human-made
landscape
features that
prevent, impede,
or divert
movement.
Set and temporally
variable obstacles such
as weather exist. Water
is an obstacle itself to
terrestrial forces.
Weather/time of day
limits visibility. Flight
ceiling and fuel
consumption limits
maneuverability, as
does anti-aircraft
defenses and
combat patrols.
Swamps,
rivers, bridges,
entrenchments,
reefs, earthworks,
sandbars, navigable
channels, fog, antiaircraft artillery,
defensive aircraft.
Navigable channels
act as avenues of
approach, however
tides and wind may
stall withdrawal along
same route.
Direct approach
from staging area
for fixed wing
aircraft is limited by
terrestrial terrain
features, fuel load,
and flight ceiling.
Roads, paths, creek
beds, navigable
channels, air
channels, valleys
and low altitude
areas.
Avenues of
Relatively
Approach and unobstructed
ground route
Withdrawal
that leads to
and/or away
from an
objective or key
terrain and does
not come under
enemy fire.
FIGURE 1. KOCOA TERRAIN ANALYSIS OF THE 1944 LANDING ON PELELIU, PALAU. IMAGE COURTESY
OF SHIPS OF DISCOVERY
FIGURE 2. METT-TC ANALYSIS OF THE BATTLE OF KEDGES STRAIT (1782). IMAGE COURTESY OF
LAWRENCE E. BABITS, NEW SOUTH ASSOCIATES
When paired with historic documents, terrain analysis provides the context
for many archeological features that remain today.
In 2018, Ships of
Discovery conducted
an archeological
survey of the reef
and landing beaches
associated with
the 1944 Battle of
Peleliu. KOCOA
military terrain
analysis was used
to interpret cultural
resources and
terrain features
encountered during
the amphibious
assault (Figure 1).
When paired with
oral accounts of the
battle, the terrain
analysis provided
context for the
many archeological
resources that
remain on the
landing beaches
today.
is used to organize
and plan tactical
operations, and
has been further
adapted for
archeological study
(Babits et al. 2011).
Still inclusive of
KOCOA terrain
analysis, METTTC addresses
five additional
components—the
acronym stands
for Mission, Enemy,
Terrain, Troops
available, Time
available, and Civilian
considerations.
forces because
Enemy covers
size of opposing
parties. Babits et
al. (2011) note that
Troops available
emphasizes combat
power over human
power; analysis is
undertaken to look
at the training and
history of individual
units in the battle
to understand how
they were effectively
or ineffectively used.
Analysis of Time
available addresses
the time needed
Mission and Enemy to carry out the
account for the plan mission, including
of action and the
time needed to
opposition forces,
rehearse, refuel,
respectively. Analysis and even rest.
of these factors
When dealing with
includes examining aerial and naval
Similar to other
overarching goals,
operations, temporal
terrain analyses,
initial objectives, and considerations
KOCOA has
motivations in the
also include tidal
limitations and
chain of command
changes and
may not be the
for both the friendly weather patterns
best choice for
and opposing
that may be
submerged
forces. Analysis
encountered.
battlefield recording. of the Enemy
Because there is
further includes
Finally, Civilian
no consideration
an understanding
considerations
for temporal
of known tactics,
addresses the
components with
equipment available, interactions
KOCOA, other
and size of the
between armed
approaches,
opposing force.
forces and civilian
discussed below,
Terrain under METT- populations. These
interactions may
may yield different
TC involves the
include detainment,
results.
KOCOA analysis.
joint operations,
evacuation, collateral
METT-TC
Troops available
damage, and/or
is only applied to
humanitarian relief.
METT-TC analysis
analysis of friendly
#11
The 1782 Battle of
Kedges Strait was the
result of increasing
tensions between a
British Loyalist flotilla
and American colonists.
Fought in Chesapeake
Bay, the engagement
lasted approximately
25 minutes, ending with
the retreat of American
vessels. Working under
an ABPP grant, New South
Associates were able to
determine likely vessel
locations using a METTTC analysis of historic
battle accounts (Figure
2). Terrain features, such
as channel location and
depth, had a significant
impact on time and troop
availability (including
vessel limitations), which
in turn impacted the
outcome. Finally, the
data generated through
analysis were used to
predict the potential
location and archeological
signature of material
culture associated with
the engagement.
PRINCIPLES OF WAR
Principles of War is an analytical framework designed to enhance understanding of past battle
engagements. While it aids in understanding
the choices made by military leaders and units,
it does not directly address terrain and terrain
features. It is a recommended secondary analysis and is not further discussed here (Babits et
al. 2011:10-12).
LEVELS OF WAR
Another military analytical tool, Levels of War,
was used to understand military engagements
from the perspectives of policymakers, military
leaders, and those on the ground. There are
three levels of war that are commonly analyzed:
the strategic, the operational, and the tactical
(U.S. Army 1982:2-3).
Levels of War begins with a broad analysis of
overarching strategy and national policy at the
strategic level (i.e. the goals of the war or campaign). This includes devoting resources to the
military goals and ensuring those at the operational level are supported. The operational
level addresses the necessary military strategy
and major operations needed to plan and execute campaigns. These sustained operations are
designed with a specific area and timeframe in
mind. Finally, the tactical level of war addresses
actions on the battlefield.
Recently, Levels of War was used
by researchers studying WWII
bomb craters found in Normandy,
France (Passmore et al. 2018). After
identifying and mapping bomb
craters seen in the landscape, the
researchers used levels of war
to identify tactical air raids that
impacted the landscape. They were
able to build on these raids by
working up through the levels of war
to identify their significance to the
larger Normandy campaign (Passmore
et al. 2018). Although outside of the
U.S., this is yet another example how
we can analyze battlefields, including
those that are underwater. The top
image here depicts LiDAR DTM while
the bottom is an aerial photograph
taken 22 June 1944 with visible craters
marked in red.
(LEFT) Image of USAAF aircraft awaiting deployment
in England. Courtesy of Naval History and Heritage
Command, (RIGHT) WWII bomb craters. Courtesy of
David Passmore
Submerged
ARCHEOLOGICAL FIELDWORK
Submerged archeological
fieldwork varies in
methodological approach but
often requires a combination
of diver and remote
geophysical survey. The
efficacy of any survey depends
on the size of the search area,
size of the targets, and the
submerged environment.
Remote sensing surveys can
cover large areas and be used
to identify submerged terrain
features and artifacts, such as
wrecks and vessel debris. They
are ineffective, however, in
detecting small artifacts such
as ordnance. Furthermore,
specialized experience and
equipment can be costprohibitive. In contrast, diver
surveys can be conducted at
lower cost and used effectively
to cover small search areas.
Two technical manuals that
are useful for understanding
underwater archeology
fieldwork are Bowen’s (2011)
Underwater Archaeology:
The NAS Guide to Principles
and Practice or Green’s (2009)
Maritime Archaeology: A
Technical Handbook. They
can be consulted for the
appropriate survey design and
methods.
for these sounds to hit the
bottom and bounce back to
the unit is directly related to
water depth and submerged
landscape features. As the data
is collected, it forms a map of
the bottom that emphasizes
any structure with noticeable
relief. The caveat to any sonar
data is that it still requires a
visual survey (either remote or
diver conducted) to confirm
findings and requires postprocessing.
SIDESCAN
SONAR
Sidescan sonar is effective
in surveying large areas and
can be paired with other
remote sensing instruments.
When surveying Charleston
Harbor from 2009-2012, the
South Carolina Institute of
Anthropology and Archaeology
(SCIAA) paired sidescan
sonar with magnetometer
to investigate submerged
American Civil War material.
Harbor defenses such as
torpedoes, obstructions,
and forts were all located
by remote sensing in search
areas created from the historic
record (Figure 3). While some
of these resources were
documented on historic maps,
remote sensing enhanced
diver survey by helping staff
anticipate size and location of
finds (Spirek 2012:94).
Sidescan sonar survey is a form
of remote sensing that uses
sound waves to map bottom
topography. Often towed
beside or behind a vessel,
the sonar unit (referred to as
a “towfish”) emits pings into
the water. The time it takes
There are several caveats
to working with sidescan
sonar instruments. As the
survey vessel is looking for
obstructions, researchers
should take precautions to
keep the towfish well above
any potential targets. This is
#14
especially important when
surveying in shallow water.
Because the sonar emissions
document seabed relief,
there are also limitations
to what can be seen in the
data. While surveying a coral
reef for WWII amphibious
landing craft, for instance,
researchers were unable
to differentiate between
coral encrusted vehicles
and naturally occurring reef
structure because both had
similar sonar profiles (Figure 4)
(Carrell 2018). For that reason,
the sonar data needed to be
paired with magnetometer
survey (discussed below) for
accurate results.
DIVER. IMAGE COURTESY OF GEORGIA
HISTORIC PRESERVATION DIVISION
Remote sensing can stand alone for documenting resources or can enhance
diver survey by anticipating size and location of finds.
Figure 3. To the left is a
sonogram of two Civil War
blockade runners, Georgiana and Mary Bowers,
wrecked off Charleston
Harbor. Image courtesy of
the South Carolina Institute
of Archaeology and Anthropology, University of South
Carolina, Columbia.
Figure 4. Below is a photogrammetry model of a submerged WWII amphibious
vehicle encrusted with coral. Image courtesy of Ships
of Discovery.
#15
Lowtech and Hightech
TECHNOLOGY
MAGNETOMETER
ADVANCES IN TECHNOLOGY
Towed magnetometers measure
disturbances in the earth’s magnetic
field created by anomalies with high
ferrous (i.e. iron) metal content. While
magnetometers typically register
metal artifacts, other objects or natural
formations will appear as anomalies
if they contain ferrous materials. The
magnetic signature of an object is
related to ferrous content. As such,
magnetometers can detect buried
or concreted artifacts such as those
embedded within a coral reef.
Geophysical instruments
such as sub-bottom profilers,
Ground Penetrating Radar
(GPR), and Electrical Resistivity
Tomography (ERT) are gaining
popularity for surveying
archeological sites. Each of
these instruments surveys
below ground level to
determine composition of
sediment and presence of
sub-surface features. While
these methodologies are often
secondary to other remote
sensing instruments, they can
be used in the delineation of
submerged and terrestrial
archeological sites.
When collecting magnetometer
data, the information is typically
displayed as a graph with associated
numerical values. This output needs
further processing to identify an
anomaly’s geographic location and size.
Additionally, the magnetometer towfish
requires a specific setup, because the
boat can create interference in the
data set. There are archeologists who
specialize in this type of technology
who assist with the planning and
implementation of surveys.
Careful planning and assessment of the
historical record and survey area should
be undertaken before any remote
sensing is conducted. For instance,
harbor survey has a high potential for
unassociated magnetic anomalies
such as anchors, aids to navigation, and
refuse. An understanding of survey aims
and end product can greatly enhance
how a magnetometer is used and can
impact efficacy of survey resources.
#16
LAUNCHING REMOTE SENSING TOWFISH. IMAGE COURTESY OF
EAST CAROLINA UNIVERSITY
In the above mentioned SCIAA survey
of Charleston Harbor, for example,
magnetometer survey aided in
identifying large submerged shot
concentrations. These aided researchers
in gauging the accuracy of Union
An understanding of survey aims and end products can greatly enhance how
magnetometer is used and can impact efficacy of survey resources.
and Confederate battle accounts (Spirek 2012:108-110). A
similar survey of submerged Revolutionary War battlefields
conducted by the Maryland Maritime Archaeology Program
(MMAP), however, found that the magnetometer was
ineffective in delineating small concentrations of shot as
the anomalies were indistinguishable from submerged crab
traps and metal refuse. Instead, magnetometer was used to
identify larger anomalies such as the shipwrecks and sunken
blockades from the battle (MMAP 2013:159).
ROV
Remotely Operated
Vehicles (ROVs) can
be used for a variety
of tasks including
photography,
videography, small
object retrieval, 3-D
modeling, and visual
survey even in low
visibility. Operated
from the surface via
tether, ROVs are often
equipped with image
and acoustic sensors
such as laser scanners,
hydrophones, and
cameras. These vehicles
can perform some of
the same tasks as divers
but are not limited by
depth and dive time.
While large vessels are
required to operate
ROVs at extreme depths,
some small scale units
can be used off smaller
plaforms at depths up
to 300 meters (975 feet).
#17
SUBMERSIBLE INVESTIGATES THE U-576, LOCATED AT A DEPTH OF 700 FEET. IMAGE COURTESY OF NOAA
FIGURE 5. AUV INVESTIGATING THE WWII BATTLEFIELD AT KISKA, AK. IMAGE COURTESY OF PROJECT RECOVER
FIGURE 6. LASER SCAN OF THE 88MM DECK GUN ON BOARD U-576. IMAGE COURTESY OF NOAA, 2DROBOTICS/SONARDYNE
Remote sensing technologies are gaining popularity in field survey because
they offer the opportunity to explore sites that were once out of reach.
AUV
During the summer of 2016,
archeologists from Monitor
Autonomous Underwater
National Marine Sanctuary
Vehicles (AUVs) are gaining
used a submersible outfitted
in popularity for use in
with laser scanning technology
submerged archeology. These to investigate a sunken WWII
systems operate without
battlefield (Howes 2016). The
tethers or controls and can
sites, a German submarine
host a suite of technologies,
U-576 and Nicaraguan
including remote sensing units freighter SS Bluefields, are only
and cameras. Use is restricted separated by approximately
to battery life and operation
200 yards, but sit in over
requires pre-programming a
700 feet of water. To record
search area into the system.
their structures, each vessel
was laser scanned, creating
Researchers operating under
a three-dimensional model
a NOAA Ocean Explorer grant showing site integrity (Figure
used four AUVs to investigate 6). Given the extreme water
a WWII battlefield at Kiska,
depths, the scans are the
Alaska (Gallimore 2018). The
first step in creating baseline
mission, which involved
documentation necessary for
searching for 10 lost American understanding deterioration
aircraft and part of the hull
and digital preservation of this
from the American destroyer
submerged battlefield.
USS Abner Read, covered an
LASER
expanse of approximately
SCANNING&
30 square kilometers. To
LIDAR
prioritize sonar targets and
ROV work, the AUVs were used
in a preliminary survey, which Light Detection And Ranging
(LiDAR) involves using
generated areas of further
waterborne and airborne
interest (Figure 5).
laser scanning to map terrain
features, including cultural
SUBMERSIBLE
materials. The scanners emit
light in the form of lasers that
Like AUVs, submersibles
hits bottom features and
can contain a number of
bounce back. As these data
technologies in addition
are collected, a bathymetric
to their human occupants
or digital elevations model
including audio/visual
of the landscape is formed.
recorders, remote sensing
Regarding terrestrial
equipment, and robotic arms
application, if the emitted light
and add-ons. While they are
limited in mobility (compared can bypass foliage and hit the
underlying terrain, it can be
to divers), they can reach
much greater depths and can used to extrapolate ground
surface and features. This is
conduct longer dives.
#19
only possible with moderate
vegetation, however.
All LiDAR requires clear waters
to operate. Airborne LiDAR can
be used to map shallow water
depths but is inefficient past
30 meters (100 feet).
DRONE
Drones are being utilized
more frequently, and as the
platforms develop to load
different equipment, they
become more useful to
archeologists. Drones can be
utilized on battlefield sites to
capture aerial photographs
that can then be used to
create photogrammetric
models of the landscape and
seascape. Drones now are
able to carry magnetometers
making it easier to reach sites
that boats cannot simply
survey.
Naval History and Heritage
Command (NHHC)
Underwater Archaeology
Branch conducted an aerial
magnetometry survey in
search for Joshua Barney’s
flotilla. The war of 1812
flotilla was pursued up the
Patuxent River by the British.
The flagship Scorpion is
believed to have been located
by archeologists, but the
project was surveying for the
remainder of the flotilla.
Pedestrian and diver surveys are an ideal way to incorporate local community
members and stakeholders into battlefield research projects.
VISUAL SURVEY
Visual survey techniques include pedestrian, snorkel, diver, and tow board surveys are
dependent on environmental limitations and personnel training. Whichever method is used,
it should be carried out in a systematic manner to ensure that the survey area is covered.
Systematic survey methods include various types of grid patterns as well as circle searches,
often used in low-visibility diving environments. The visual survey should also be accompanied
by some form of recording mechanism that allows for the location and details of finds to be
documented.
M E T A L D E T E C T I ON
Handheld metal detectors are supplemental tools that can greatly aid in identifying materials
while in the field. Unlike magnetometers, metal detectors create their own magnetic field.
When in the presence of metals (both ferrous and non-ferrous), the decay of the magnetic field
slows, resulting in a positive “hit.” While training and familiarity with the detector is necessary
for successful results, metal detectors are less costly than other forms of remote sensing
equipment. For the most accurate results, any metal detecting survey should be conducted in a
systematic fashion that can be repeated in the future.
Diver survey using metal detecting was the primary methodology used by the Lake Champlain
Maritime Museum (LCMM) to systematically survey bottomlands associated with the Battle
of Valcour Island (Cohn et al. 2003:25). Recreational volunteer divers worked with trained
archeologists to conduct metal detecting transects of the survey area. Any positive metal
detecting hits were recorded, along with visible artifacts, to create an extended site plan of the
battlefield and delineate site extents.
DIVER RECORDING A MAGNETIC ANOMALY. IMAGE COURTESY OF EAST CAROLINA UNIVERSITY
#20
Visual survey techniques include pedestrian, snorkel, diver, and tow board
surveys are dependent on environmental limitations and personnel.
U.S .SPECIAL FORCES VETERAN VOLUNTEERING TO CONDUCT A CIRCLE SEARCH. IMAGE COURTESY OF EAST CAROLINA
UNIVERSITY
DIVERS CONDUCTING IN SITU CORROSION SURVEYS ON WWII AIRCRAFT IN SAIPAN. IMAGE COURTESY OF WESTERN AUSTRALIA
MARITIME MUSEUM
#21
Recording Features and
RECORD KEEPING
FIGURE 7. SURVEY DRONE FITTED WITH MAGNETOMETER. IMAGE COURTESY OF NAVAL HISTORY AND HERITAGE COMMAND
#22
HAND DRAWN ARTIFACTS FROM THE VALCOUR BAY PROJECT. DRAWINGS COURTESY OF THE LAKE CHAMPLAIN MARITIME
MUSEUM
All projects face different
requirements
for documenting submerged archeological features
depending on overarching aims and goals. Regardless of a project’s scale, it is important to
document all activities that occurred on site. Field journals are traditionally kept by all members
of an archeological project; these serve to document daily activities, areas surveyed, problems
encountered, and present a brief overview of findings. Daily logs and journals are usually further
accompanied by images and/or site, feature, and artifact drawings.
Because battlefield projects address defining features with set geographic coordinates, a
record of associated geographic locations should be kept for every feature surveyed in the
field. This record should also include associated metadata, such as the geographic coordinate
system, projection, and instrument accuracy.
Pre-made recording forms, also known as pro-formas, can greatly enhance organization and
record keeping. Prior to any fieldwork, it is useful to develop forms such as photograph and
video logs, dive or snorkel logs, metal detecting logs, GPS logs, and defining feature recording
sheets. Various examples of these forms exist and can easily be tailored to individual projects.
#23
Final
PRODUCTS
In all likelihood, the study of
a battlefield was undertaken
because it was deemed
significant to a stakeholder
or group of stakeholders.
While not all interested
parties will be involved in
site research or visitation, it
is important to disseminate
results of the study in a timely
manner to ensure inclusivity.
Furthermore, it may also
encourage interest in site
history, which leads to further
involvement in site protection,
outreach, or education.
threaten the submerged
battlefield are considered
immediate threats. For
example, installation of a
pier or bridge over a historic
submerged battlefield could
have immediate negative
consequences for submerged
resources. Unfortunately,
looting and illicit removal of
resources is another threat
frequently associated with
submerged sites. These threats
should be addressed with their
potential impact on battlefield
resources.
generating geographic data.
For more information on GIS
data, visit https://www.nps.gov/
crgis/crgis_standards.htm.
Repositories are institutions
designed to store data over
the long-term. If possible,
researchers should budget
for long-term data storage
in an appropriate repository
and should plan to maintain
duplicate copies of data.
Unfortunately, one of
the realities of studying
submerged battlefields are
encounters with relic hunters.
A variety of public outreach
Long-term threats are those
As artifacts and sites of
and information sharing
that, while not immediate,
combat are used to interpret
options are recommended to will eventually impact a
submerged battlefields, the
reach a wider audience than
battlefield’s resources and
removal or destruction of
formal reporting can achieve.
interpretation. Environment,
these resources negatively
Social media publications,
future development, and
radio advertisements and
prolonged human activity can impacts battlefield integrity.
As a researcher, it is important
interviews, public meetings,
all be factors that contribute
to protect site integrity by
newspaper articles, websites
to loss of battlefield integrity.
working with local agencies to
or blogs, archeological site
Of these, erosion and
reports, and conference
deterioration from the aquatic determine the level of detailed
information shared with the
presentations all reach
environment are threats that
public. Often this means
different populations and can many submerged resources
a redaction of geographic
be a means of inviting different face.
coordinates in publicly
stakeholder groups into
released reports to protect site
ongoing research.
Any data or research
generated during a project has integrity until a management
plan is in place. Other reasons
SITE INTEGRITY
the potential to become the
to redact data from reports
best record of a battlefield’s
may be for safety (e.g. large
All final reports should
resources if site integrity
quantities of UXO on site),
address site threats and
is lost. Data and metadata
confidentiality (if aspects of
integrity. Threats can be
should be recorded in a way
site history remain classified),
further differentiated into
that accounts for long-term
preservation and accessibility. or sensitivity (e.g. human
two categories: immediate
remains were located that
threats and long-term threats. Federal institutions maintain
Ongoing development and/
data standards that are highly correlate to a known loss).
or landscape changes that
recommended for researchers
#24
UXO & In-field
Identification
The archeological survey of historic
submerged battlefields increases the
likelihood of encountering historic
munitions, a concern to archeologists.
Unexploded ordnance (UXO), is a term
that describes explosive weaponry and
ammunition that did not detonate, either
due to failure or non-deployment. There
are two types of historic munitions that
might be encountered on sites: explosive
projectiles and warheads (e.g. bombs,
grenades, artillery shells, mines, missiles,
submunitions, and rockets) and nonexplosive projectiles (e.g. small arms
ammunition).
The accepted protocol for UXO involves
three R’s—recognition, retreating, and
reporting the object to the appropriate
government authority, such as local law
enforcement. Prior to fieldwork, project
personnel should familiarize themselves
with potential historic munitions that might
be found on the battlefield. If UXO is found
or suspected on site, personnel should not
touch, move, bury, or clear sediment from
the object. The primary concern should be
to clear the immediate vicinity of personnel
until the potential hazard has been
assessed and mitigated by appropriate
authorities trained in UXO handling and
removal.
#25
JAPANESE MEMORIAL ON SUBMERGED WWII AIRCRAFT SITE IN SAIPAN. IMAGE COURTESY OF SHIPS OF DISCOVERY
Document
PHOTOGRAMMETRY
Photogrammetry is the process of recording 3D objects using 2D images.
Software programs then use images to extract measurements of 3D objects and create digital models. Over the past decade, photogrammetry
has revolutionized archeology as it allows for rapid site recording via photography. After the images are taken (often over the course of a single site
visit), the model can be built and used to create site plans and take scaled
measurements. The models can also be shared online or even printed in 3D
as outreach materials.
& Record
Photogrammetry models of WWII vessels and aircraft associated with the
Battle of Saipan have been created as digital outreach materials by researchers at East Carolina University. These models have not only aided in site
recording but also have been used to introduce non-diver stakeholders to
submerged heritage.
BACKGROUND IS A PHOTOMODEL OF AN AICHI E13A ‘JAKE’ FLOATPLANE LOCATED IN SAIPAN, CNMI. IMAGE
COURTESY OF SHIPS OF DISCOVERY
LEFT: DIVERS INVESTIGATING SUBMERGED AMPHIBIOUS VEHICLE. IMAGE COURTESY OF SHIPS OF DISCOVERY. RIGHT: SURVEY
TARGETS ON A HISTORICAL CHART. IMAGE COURTESY OF GEORGIA HISTORIC PRESERVATION DIVISION
HUMAN REMAINS
CONCLUSION
Submerged battlefield archeology involves the
systematic study of battles that took place on,
near, or under water. This manual was designed
to offer insight into current submerged battlefield
research by addressing the field methodologies,
battlefield analysis approaches, and technological
innovations that are currently shaping battlefield
archeology research.
While the parameters for every survey will differ
(based on environmental constraints, resources
available, and overarching research aims), the end
goals of battlefield research, outreach, protection,
and preservation unite submerged battlefield
projects.
The study of submerged American battlefields
offers researchers, community members, and
stakeholders opportunities to understand and
interact with events that define our nation’s
history. Ongoing submerged battlefield research
will strengthen our shared understanding of
the role waterways played in past conflicts.
Furthermore, continued battlefield studies will aid
in the preservation of sites that honor the sacrifices
and bravery of those involved.
#28
The potential to find human remains
on a submerged battlefield is in
some instances better than on
land due to the preservation that
an anaerobic environment can
provide. There are Federal and State
laws that apply to the discovery of
human remains on archeological
sites. There is also a Federal agency,
the Defense POW/MIA Accounting
Agency (DPAA), whose mission
it is to account for lost service
personnel. Typically, the first point
of contact is local law enforcement
and the SHPO. Should one find
human remains, it is important to
report them immediately and be
respectful.
ment, Obstacles, and Avenues of Approach and
Withdrawal. A military terrain analysis used to understand physical space associated with conflict.
Levels of War: A military strategic analysis that examines engagements from the tactical, operational,
and strategic levels.
METT-TC: A military analysis used to examine operations that addresses the Mission, Enemy, Terrain,
Troops available, Time, and Civilian considerations.
NHHC: The Naval History and Heritage Command is
an Echelon II command responsible for the preservation, analysis, and dissemination of U.S. Naval history and heritage located at the historic Washington
Naval Yard.
GLOSSARY
Battlefield Archeology: the study of military technologies, features, and conflicts
through material evidence.
Battlefield Boundary: the historical and
archeological area in which the battle
took place.
Conflict Archeology: the study of technological, social, and cultural tensions between people through material evidence.
Core area: the area where the most significant fighting took place.
DPAA: The Defense POW/MIA Accounting
Agency is the Federal agency responsible
for providing the fullest possible accounting for our missing personnel to their
families and the nation.
GPS: Global Positioning System.
KOCOA: Stands for Key terrain, Observation and fields of fire, Cover and conceal-
PotNR: Potential National Register boundary. This
is the area of the battlefield which retains historic
integrity. The PotNR may have been identified in a
previous study or it may require further delineation.
Principles of War: Guidelines used by the U.S.
armed forces to prepare for a military engagement.
Remote Sensing: Non-intrusive methodologies
used to gather geophysical data.
SHPO: State Historic Preservation Office(r).
Sunken Military Craft Act: Legislation enacted in
2004 which protects all U.S. sunken military craft
from unauthorized disturbance. Foreign sunken military craft located in U.S. waters are also protected.
Implemented and enforced by NHHC.
THPO: Tribal Historic Preservation Office(r).
Towfish: The survey instrument towed behind a
vessel to collect data. The instrument can be outfitted with various sensors such as a magnetometer or
sidescan sonar.
UXO: Unexploded ordnance or historic munitions
which have not detonated.
#29
REFERENCES CITED AND ADDITIONAL RESOURCES
American Battlefield Protection Program (2019) About Us. American Battlefield Protection Program, National Park Service, Washington, DC. www.nps.gov/abpp.aboutus.htm.
Babits, Lawrence, Christopher T. Espenshade, and Sarah Lowry (2011) Battlefield Analysis: Six Maritime Battles in Maryland Revolutionary War and War of 1812. New South Associates, ABPP Report.
Stone Mountain, GA.
Bowen, Amanda (2011) Underwater Archaeology: The NAS Guide to Principles and Practice.
Wiley-Blackwell, Hoboken, NJ.
Carrell, Toni L. (2018) Mission Plan: Peleliu’s Forgotten World War II Battlefield. NOAA Ocean Exploration and Research, National Oceanic and Atmospheric Administration. https://oceanexplorer.
noaa.gov/explorations/18peleliu/background/plan/plan.html.
Cohn, Arthur B., Adam I. Kane, Christopher R. Sabick, and Edwin R. Scollon (2003) Valcour Bay Research Project: 1999-2002 Results from Archaeological Investigation of a Revolutionary War Battlefield in Lake Champlain, Clinton County, New York. Lake Champlain Maritime Museum, Survey
Results. Vergennes, VT.
Conlin, D. L., and Russell, M. A. (2006) Archaeology of a Naval Battlefield: H. L. Hunley and USS Housatonic. International Journal of Nautical Archaeology 35: 20–40.
Gallimore, Eric (2018) Finding World War II Wrecks with Robots. NOAA Ocean Exploration and Research, National Oceanic and Atmospheric Administration. https://oceanexplorer.noaa.gov/explorations/18kiska/background/tools/tools.html.
Green, Jeremy (2009) Maritime Archaeology: A Technical Handbook. Routledge, London.
Howes, Megan (2016) Exploring World War II’s Battle of the Atlantic: Part II. NOAA Marine Sanctuaries, National Oceanic and Atmospheric Administration. https://sanctuaries.noaa.gov/news/nov16/
exploring-wwii-battle-of-the-atlantic-part-2.html.
Maryland Maritime Archaeology Program (2013) Naval Engagements of the Revolutionary and 1812
Wars in Maryland. Maryland Maritime Archaeology Program, ABPP Report. Boston, MA.
McKinnon, Jennifer F. and Toni L. Carrell (2015) Underwater Archaeology of a Pacific Battlefield:
The WWII Battle of Saipan. Springer Press, NY.
Passmore, David G., David Capps Tunwell, and Stephan Harrison (2018) Revisiting the US military
“Levels of War” model as a conceptual tool in conflict archaeology: a case study of WW2 landscapes in Normany, France. Paper presented at the 2018 Fields of Conflict Conference, Mashantucket, CT.
Roth, Madeline and Jennifer McKinnon (2018) “Unidentified Planes Sighted”: The Application of
KOCOA Military Terrain Analysis to Aerial Combat. In ACUA Underwater Archaeology Proceedings,
Matthew Keith and Amanda Evans, editors, pp. 181-186. Advisory Council on Underwater Archaeology, New Orleans, LA.
Spirek, James (2012) The Archaeology of Civil War Naval Operations at Charleston Harbor, South
Carolina, 1861-1865. South Carolina Institute of Archaeology and Anthropology, ABPP Report. Columbia, SC.
Stanley, Richard L. (1986) Intelligence Preparation of the Battlefield. American Intelligence Journal
7(3):24-27.
U.S. Army (1982) Operations: FM 100-5. United States Army Field Manual 100-5 . Washington, DC.
WATERMARK: PROPELLER FROM A KAWANISHI H8K “EMILY” SEAPLANE. IMAGE COURTESY OF SHIPS OF DISCOVERY
SUBMERGED BATTLEFIELD-RELATED ORGANIZATIONS
AMERICAN BATTLEFIELD PROTECTION PROGRAM
The American Battlefield Protection Program
(ABPP) promotes the preservation of significant
historic battlefields associated with wars on American soil. The goals of the program are 1) to protect
battlefields and sites associated with armed conflicts that influenced the course of our history, 2)
to encourage and assist all Americans in planning
for the preservation, management, and interpretation of these sites, and 3) to raise awareness of the
importance of preserving battlefields and related
sites for future generations. The ABPP focuses
primarily on land use, cultural resource and site
management planning, and public education.
DEFENSE POW/MIA ACCOUNTING AGENCY
The Defense POW/MIA Accounting Agency’s mission is to provide the fullest possible accounting
for our missing personnel from past conflicts to
their families and the nation. Within this mission,
they search for missing personnel from World War
II (WWII), the Korean War, the Vietnam War, the
Cold War, the Gulf Wars, and other recent conflicts.
NAVAL HISTORY AND HERITAGE COMMAND
The Naval History and Heritage Command (NHHC),
headed by the Director of Naval History, is an Echelon II command headquartered on the Washington Navy Yard, D.C. Its vision is to serve our nation,
by using the power of history and heritage to enhance the warfighting capability of the U.S. Navy.
Its mission is to preserve and present an accurate
history of the U.S. Navy.
STATE HISTORIC PRESERVATION OFFICE(R)
A State Historic Preservation Officer is the appointed official in each of the 59 states, territories
and the District of Columbia who is responsible for
the management and protection of historical and
archeological resources. The SHPO Federal mandate is set forth in the National Historic Preservation Act of 1966.
TRIBAL HISTORIC PRESERVATION OFFICE(R)
Tribal Historic Preservation Officers are officially
designated by a federally-recognized Indian tribe
to direct a program approved by the National Park
Service. THPOs assume some or all of the functions of State Historic Preservation Officers on
Tribal lands. This program was made possible by
the National Historic Preservation Act of 1966.
SURVEY OF FORT FISHER, THE CIVIL WAR’S LARGEST AMPHIBIOUS BATTLE. IMAGE COURTESY OF EAST CAROLINA UNIVERSITY
Grant Agreement No. GA-2287-17-015
American Battlefield Protection Program
Submerged Battlefield Survey Manual
Jennifer F. McKinnon, Madeline Roth, Toni L. Carrell
Ships of Exploration and Discovery Research, Inc.
2020
This material is based upon work assisted by a grant from the Department of the Interior, National Park Service. Any opinions, findings, conclusions,
or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of the Interior.
PREDISTURBANCE SURVEY OF WAR OF 1812 SITE AT MACKINAC ISLAND, MI. IMAGE COURTESY OF EAST CAROLINA UNIVERSITY