Each episode of the series is about the heroism of the USN, USA (Army), Australians, British, Filipinos, Indonesians, and other Allies.
When I lookup (DDG/Google/Bing) information about the submarines mentioned/detailed in the episodes, I get the same basic information that is in each pertinent episode... I consider this to be a high compliment to the facts presented in each episode. Of course, there are probably some inaccuracies.
This series doesn't attempt to instill more drama than actually existed ... which must have been significant ... it decreased the drama and let us, the viewers, decide for ourselves.
Anyone that has actually been within a WWII submarine nowadays (such as the USS Torsk, SSN-423, now in Baltimore, MD, near the National Aquarium, USS Constellation, and USCG Cutter 37) would have additional awareness of what the USN submarine crews had to deal even when not in action. The subs are quite small, not much space, except for the racks of torpedos which took a lot of room.
The series even touched on the sensitive subject of the significant issues with the Mark 14 torpedo, which had major multiple problems, all covered-up by one person in the USN.
The number of future stars in the series is phenomenal: Carl Betz, Deforest Kelley, Russell Johnson, Joe Flynn, Leonard Nimoy, Kurt Kreuger, Simon Oakland, Dennis Weaver, Richard Crenna, Chuck Connors, Mike Connors ... too many to mention. Amazing cast.
Great series.