Angus' father Charles, the former handyman, is a sailor in the Royal Navy, missing since his ship was sunk in the war a year earlier.

One day, while collecting seashells, Angus discovers a large, mysterious egg in the sand, and an unknown creature hatches, which he calls 'Crusoe' after Robinson Crusoe.

Royal Artillery troops arrive at the house, commanded by Captain Thomas Hamilton – a friend of Lord Killin.

After a few days of training, he escapes, returning to the lake and a full-grown Crusoe, who gets Angus to ride on its back.

The next day, Captain Hamilton takes the MacMorrow family to a hill overlooking Loch Ness; Crusoe is almost hit by an exploding shell during a firing demonstration.

Angus interrupts to save Crusoe from injury or death, enraging Hamilton and irritating his mother, who doesn't believe him.

Crusoe rises, still in shock and fear from the earlier bombardment, nearly bites off Angus's hand before sinking back into the loch.

Crusoe then surprises the soldiers, capsizing their boat but not before one of them sends out an SOS to Hamilton, who thinks the Germans are attacking.

Director Jay Russell first read Dick King-Smith's book years before the film was actually made.

"[8] The scenes in and around the MacMorrow family's house were shot on the 100-year-old Ardkinglas Estate on the shores of Loch Fyne in Scotland.

And many of those shots involved the creature (Crusoe) interacting with water, which, in terms of the history of computer graphics, has always been a particularly difficult substance to deal with.

[10] In terms of the design of the creature, Weta Digital tried to not humanise him but instead based some of his expressions on real animals such as a dog.

The Water Horse was formerly scheduled for two different release dates in North America: 21 September 2007 and 7 December 2007.

[12][13] No reason has been given as to why either date was dropped, but the film was released across 2,772 screens[14] in the United States, Canada and Mexico on Christmas Day of 2007.

The first was a teaser created specifically for the Rock Ness Music Festival on 9 and 10 June,[19] but was leaked onto the internet and later pulled.

[26] Another website was created by the film's production companies, asecretthisbig.com, and is dedicated to the examination of the Loch Ness Monster's existence in reality.

It takes a classic tale and infuses it with extra imagination, sly humor, heart, and inventive special effects.

Hammond said the character Angus is "expertly played by Alex Etel," said the film was "skillfully directed by Jay Russell", and said the special effects were "stunning" and "rival the year's best.