With its dewy-eyed demeanour and windswept air, it’s tough not to give in to the cloyingly adorable beastie that is The Water Horse: Legend of the Deep. Alas, the champion cast (Millions’ Alex Etel as the boy-hero, Emily Watson as his gracefully troubled mother) and perfect setting (New Zealand standing in for the Scottish highlands) can only float Jay Russell’s film so far — about three-quarters into the run time — before it gets bogged down in boy-and-his-monster clichés, mottled coming-of-age sophistry and CGI of diminishing returns.

Etel is Angus, a highland laddie who spends the early days of World War II combing the shores of Loch Ness and fighting to maintain the fantasy that his sailor father is coming home from sea. While his mother Anne, head housekeeper at a Scottish Lord’s estate, is momentarily distracted by the task of billeting a British artillery regiment, Angus discovers a mysterious egg with mythic content: a sea creature of legend, which he names Crusoe. Only Angus’ protective older sister and the war-weary new groundskeeper (Ben Chaplin) are in on the discovery at first, but a conflict of interest with the Royal Artillery is inevitable, as is the looming Free Willy climax.

There are nice moments here, with Watson and Chaplin doing particularly fine work overcoming the wet-noodle script and rote story arc with just their eyes and a few well-placed gazes. Stare long enough at this potentially captivating arrangement of actors and scenery, however, and The Water Horse takes the shape of a standard paint-by-numbers scheme.