The wretched alcoholic is Thomas Nickerson, once the cabin boy on a Nantucket whaling ship called the Essex, and one of just a handful of sailors who survived an attack by a massive, vengeful, white whale in 1820.

It’s an important moment. Melville has come in search of the story that will allow him to take his mind “where one does not want to go”; a story that will allow him to weave fact, fantasy, speculation, opinion, allegory, belief, doubt, literary history, good and evil, hope and despair into a monster of a book.

Nickerson has never told the tale before. The fate of the Essex lies in the 19th century public imagination somewhere between myth, cover-up and conspiracy theory. But Melville wants out of a place where “knowledge ended and speculation began”. He needs this story to be true. He needs all its terrible details.

Whisky and three hundred dollars loosen Nickerson’s tongue and he becomes the narrator of In the Heart of the Sea. He also begins a journey to redemption. The trouble is, none of this ever happened, and the film’s main narrative device is one of many liberties taken with fact in the interests of drama.

In fact, history records that the 14 year old Thomas Nickerson did survive the ramming and sinking of the Essex and subsequent nightmare of life and death in open boats hundreds of miles from either land or passing ships. However, he also recovered and returned to sea where he carved a successful career. He even wrote about his ordeal in a manuscript that was lost until 1960 and not authenticated until 20 years later. We cannot be certain how accurate it is but we know he was not trapped in silent trauma.

The literary ambitions of the Essex’s first mate, Owen Chase, were better served. He returned home to Nantucket in June 1821 and, before the year was out, completed an account he called Narrative of the Most Extraordinary and Distressing Shipwreck of the Whale-Ship Essex. It was this book that introduced Melville to the detail of the sinking and, what is more, another fierce white whale known as Mocha Dick had been much talked about within the whaling community since around 1810 and subsequently cruised around newspapers and periodicals.

None of this means In the Heart of the Sea is a disastrous movie; in fact, far from it. But there is something about the increasingly prevalent and often restrictive conventions of modern film and television drama that can alienate audiences as easily as they are meant to captivate them. Thus Thomas Nickerson becomes an old drunk with an old wife who adores the man he once was. Can she get him back?

Melville’s money is all he and his wife “have in the world”. This is meant to create jeopardy - will he get a return on his investment? (In fact, Moby Dick was a financial disaster for Melville. Ahead of its time it was published first in England to poor reviews, a lead that was followed in America, and sales were low.)

Owen Chase is passed over for promotion to skipper because the job goes to Pollard, from a prominent Nantucket whaling family. Chase may be by many nautical miles the better sailor, but he is also a landsman, sea-going riff-raff. Pollard is arrogant and was born with a sneer on his lips and an inferiority complex. This ignites a class war, an ill tempered contest that ends in a respectful, slightly bonkers draw.

Chase has some issues with an unseen father and lets off steam in the early minutes of the film about him and his dirt poor home - steam which dissipates into the atmosphere and bears no further relevance to the plot, apart from the need to fill the Essex with whale oil, whatever the cost. Chase also wants to be someone; a big shot. His beautiful wife, pregnant with a child he will not see until his return, just wants her beloved Owen, a family, and to be happy.  

In fact, it is true that Chase came back to a 14 month old daughter he had never clapped eyes on. His marriage also ended and eventually he succumbed to severe mental illness. With old Tom Nickerson in place as storyteller, his younger self is free to be the innocent on board and the means by which all the wonder and disgust of whaling is channeled to the audience.

These are extraordinary set pieces full of dizzying movement and sound, and proof that the moment when CGI is utterly photo realistic is not far away. They reconstruct with great power a way of life that depended on skill, courage, and an intimacy with the natural world I can only guess at.

The poor souls who survived the Essex being “stoved by a whale” were adrift so long before rescue, the filmmakers seem to have panicked that here was a section of story with precious little action. Hence the whale turns out to have obligingly followed them and launches another murderous attack on their small boats. It seems this never happened either. A braver version of the Essex story might have dwelt longer and with more artistry on what it means to be abandoned without any apparent hope.

Perhaps the ambition of the recent TV movie The Whale should have been fused with the budget of In the Heart of the Sea. All the performances from the likes of Chris Hemsworth, Ben Whishaw and Cillian Murphy are rock solid but none of them stand out, and had the script stayed more loyal to history there would have been more scope to concentrate on character. 

The phrase ‘based on true events’ with which this and many other films begin is an increasingly troubling one. It is meaningless because we have no idea how firm the foundation is, and also because we don’t look to drama for objective truth. But when true events clash, as they all too frequently do, with the desires of writers and directors to make something that won’t let you go, something that is accessible and busts the block, the result can all too easily be doubt about accuracy and honesty, and doubt is the sworn enemy of engagement.

If you go to In the Heart of the Sea expecting insight then you are likely to be disappointed. If you go expecting an extraordinary spectacle of gob smacking sights and the unthinkable made real, then you will have plenty to keep you occupied. Two hours passed very quickly and I would heartily recommend the film. For my part I wish the enormously gifted director Ron Howard had made a new adaptation of Moby Dick. The question, “Monsters! Are they real?” has never felt more relevant.

In the Heart of the Sea is now showing at FACT, buy your tickets here.