“In the Heart of the Sea” opens Friday at Point, Palace, AMC Fitchburg and Sundance. PG-13, 2:02, two stars out of four.

“If I don’t write it, I fear I shall never write again. If I do write it, I fear it won’t be good enough.”

That’s a young Herman Melville (Ben Whishaw) agonizing over writing the novel that will be “Moby Dick,” but I wonder if director Ron Howard and screenwriter Charles Leavitt had similar misgivings about making “In the Heart of the Sea.” Technically the film isn’t a straight adaptation of Melville’s novel, but based on the real-life events that supposedly inspired it (made into a nonfiction book of the same name by Nathaniel Philbrick). But the shadow of the whale and of the Great American Novel loom large over a weak screenplay and some stock seafaring characters.

The film features an unnecessary and distracting framing device in which young Melville — smarting over not being as famous as the better-known Nathaniel Hawthorne — comes looking for a story at the home of Tom Nickerson (Brendan Gleeson), an old seaman who was one of the few survivors of the Essex, a whaling ship that sank in 1820. Melville thinks there’s a hole — a whale-sized hole — in the official report of the disaster, and comes looking for the real story.

The majority of the film is told in flashback, but not from the point of view of young Tom (Tom Holland), but from hunky first mate Owen Chase (Chris Hemsworth). Chase is an experienced enough seaman to command his own ship, but he’s not from one of Nantucket’s prominent whaling families, so he’s saddled with second-in-command behind the less-experienced, arrogant Capt. Pollard (Benjamin Walker).

The Essex crew, stuffed full of familiar stereotypes, heads off looking for whales, eventually chasing rumors of a vast field of whales in uncharted waters of the Pacific Ocean. They find them — along with a great white whale (well, mottled grey-and-white, sort of a deep-sea camo) more than capable of defending the herd from the whalers.

“In the Heart of the Sea” is certainly a beautiful film to look at, with hypnotic blues and grays that seem almost painterly; the silvery sheen of sunlight on water is especially mesmerizing. Between these magnificent shots, Howard and cinematographer Anthony Dod Mantle insert quick shots of fixed cameras placed seemingly at random, focusing in extreme close-up on a rope pulled tight or a pen dipping into an inkwell.

It’s a distractingly showy effect, one seemingly inspired by the whaling documentary “Leviathan.” The result is often a series of impressive shots that don’t string together into an effective scene — we never know where we are or what we’re supposed to be looking at. This sense of chaos does work in the scenes of whale attacks on the Essex, the visual and sound design effectively suggesting the sheer bulk and fury of the great white whale as it smashes the ship to matchsticks.

But when the whale is off-screen, the movie founders, making the occasional feint at grander themes about man vs. nature without really following through. Nickerson’s recollections suggest that Chase is a man driven by greed into disaster, but Hemsworth’s one-note performance allows for nothing other than bland heroics. Is it weird I can buy him as a Norse god easier than as a sailor or a hacker (“Blackhat”)?

The film features a bunch of good character actors (Whishaw, Gleeson, and Cillian Murphy) punching beneath their weight with Leavitt’s paint-by-number characterizations. The Whishaw-Gleeson scenes inserted through the movie are particularly distracting, suggesting that Melville’s quest to write the novel is on a par with Chase’s quest to vanquish the whale. Yeah, not quite.

There’s a scene about a half-hour into the movie when the rash Pollard drives the Essex into the middle of a storm — largely because he can. Waves crash, men scream, thunder rolls, the Essex barely survives. It’s a cool scene — but it’s only cool, with no emotional impact. Because we sense that Howard included the scene just because it would look cool — just because he could.