Trivia

In traditional Scottish mythology, 'The Water Horse' aka 'Kelpie' is a terrifying people-eating "boogeyman." This beast appears in a pleasing form to lure unsuspecting victims (usually children) to play with it. Once the unfortunate soul had mounted the Kelpie, it would trap the victim with glue excreted from its skin, and drag him or her down to a watery death. Another kind of Kelpie took the form of a handsome man who targeted young women, analogous to the Dracula and Nosferatu of Eastern Europe. Society used these legends to protect young people by teaching them to be wary of adult strangers and dangerous natural formations. Kelpie stories come from all over Scotland, and are not exclusively associated with Loch Ness. It was only in the 1930s, after the popularity of early stop-motion dinosaur films such as The Lost World (1925) and King Kong (1933), that the standard image of Scottish lake monsters was revised to be shaped like a dinosaur or a plesiosaur. Their nature was subsequently changed to become docile, cute and cuddly, because this image is more convenient for creating a tourist attraction. The association of these monsters with Loch Ness specifically, only came about because the first published photo of such a "creature" was made there, around 1933. After that picture (called the "Surgeon's Photo" and seen frequently in this film) became world-famous in 1934, several similar monsters were "sighted" in various locations across Canada, and given names such as Ogopogo and Cadborosaurus. During the Great Depression, happy novelties in the news were popular, so they were covered extensively. The fact that these "sightings" are so convenient for entertainment culture and the tourist industry, suggests that the phenomenon is commercial rather than biological.

Originally, The Chronicles of Narnia: Prince Caspian (2008) was supposed to be released in Christmas 2007, but when The Water Horse was announced to have that release date, Narnia was pushed back six months.

The iconic photo shown in this film, taken by the "Surgeons" and purportedly showing a monster, was cropped to make the object in it seem big, but the unaltered photo shows a very small object in the middle of Loch Ness. If it's not simply a toy submarine with a "head" attached (as one of the original presenters allegedly "confessed" in the 1970s), then it could also be the forehead and trunk of a local circus elephant taking a swim in the lake when the circus was not performing.

For the design of Crusoe, Weta Digital tried to not humanise him but instead based some of his expressions on real animals such as a dog. "We wanted to create something which seemed familiar, but was unique at the same time," said Russell. "As a result, Crusoe's face is a combination of a horse, a dog, an eagle and a giraffe." When creating his movements and body shape at various stages of growth, the animators referenced animals ranging from baby birds to seals to whales.

Emily Watson later appeared in the similarly titled War Horse (2011). In both movies she plays the mother of the lad who cares for the titular animal. Both are set during a World War - Water Horse during the Second, and War Horse during the First.