Starring Chris Hemsworth. Rated PG.

It is astonishing to think that frail wooden vessels, powered only by wind and tide, could and did undertake vast voyages, steering by sun and stars. Whalers were among the toughest of their voyagers, hunting the massive creatures on trips that could last three years.

The perils of these expeditions, and the great skills of their crews, are amply illustrated in Herman Melville’s novel Moby-Dick, itself based on the same event depicted here. In the Heart of the Sea recounts the wreck of the whaleship Essex in 1820, bookending those events with scenes of Herman Melville himself interviewing the last survivor.

It is a story rich with action and tragedy. As a movie, unfortunately, it is leaden and dispiriting to the point where I was wondering what went wrong.

Ron Howard is a very good director, and Chris Hemsworth is as charismatic a lead as you could wish to portray Owen Chase, first mate of the ill-fated Essex. He has an in-and-out Nantucket accent and not much to say, but he ably sells his resentment and conflict with the better-connected Essex skipper George Pollard, portrayed by that skilled performer and former vampire-hunting president Benjamin Walker.

The production values are fine when it comes to the docks and crafts of New England in the age of sail, and the Essex itself has been lovingly reproduced, masts and cordage in plenty, pawls clacking, giant cauldrons rendering fat from the flensed strips of blubber.

The glaring and conceivably fatal flaw is that the intact whales are so obviously computer-generated. The sea-action graphics in this movie are comparable to Assassin’s Creed IV: Black Flag for the PS4. That’s impressive in a game, but in a contemporary big-budget epic, it is a distraction. At no point does it seem like anyone is actually threatened by a murderous whale.

The resultant scenes of despairing abandonment become, alas, only too relevant.