BOOK REVIEW : A Hearty Helping of High-Seas High Jinks : FISHBOY, A Ghost’s Story <i> by Mark Richard</i> . Doubleday; $19.95, 227 pages

Since Mark Richard reveals the narrator’s secret in the subtitle of this seafaring Gothic comedy, there is no harm in revealing it a little more. “Fishboy,” his much-buffeted midship mite and cook’s helper, is not just a ghost but soup or, rather, the steam off soup.

I suppose that the surreal doings aboard Fishboy’s nightmare trawler could be assigned to the I-alone-am-left-to-tell-the-tale line of “Moby Dick” and “The Rime of the Ancient Mariner.”

You would have to conceive the Mariner and Ishmael as plates of talkative chowder. You would also allow for periodic breaks in the doomsday visions to make way for the “Ballad of the Eddystone Light.” Like the lusty lighthouse keeper, the trawler’s captain is besotted with a mermaid, and the results are even more zippily far-fetched. Zippy is somewhere in there too.

Fishboy starts out as a feral child living in a cardboard box. He works at a fish-processing plant on a mythical and unnamed seashore that resembles the Maryland or Carolina coast. He lives on fish scraps and garden okra and is terrorized by a monstrous woman named Magine. Like Pirate Jenny, and similarly downtrodden, he dreams of rescue and revenge until, sure enough, a dark ship pulls in one night and its tattooed captain appropriates Fishboy’s dinner, makes a kite of his cardboard shack and burns down the fish plant.

“I am on you like a tick,” Fishboy thinks worshipfully, and he manages to stow aboard. “I think you can either cook or you can swim,” the captain decrees. These are mediocre choices, since Fishboy has just seen Lonny, the pedophile mate, use a huge axe on the previous cook for serving greasy eggs.

With Lonny’s orders for steak, biscuits, collard greens and fluffy eggs ringing in his ears, he limps down to the rat-infested galley. “I drug myself along, hearing everything he asked for taking piece after piece of hope from me of ever getting through my life not split in two with an ax.”

It is a ship of surreal hobbledehoys. The captain, obsessed with the mermaid who loved and abandoned him on a far volcanic island, has tattooed himself with sea charts in hopes of finding the island again. He has attached a huge net to his ship on the chance that it will catch her, and he swims off the ship’s side, searching. Watt, the steersman, has no skin and is a dreadful sight, but he is Fishboy’s kindly protector. Dench spends day and night lashed high on a mast to keep watch for the rogue wave that will finish them.

There are an idiot, a dead sheriff and two convicts who are soon dead too. Before long there is another cook, much to Fishboy’s relief. The Coast Guard has dumped him on board because he has smallpox. By the time Fishboy gets boiled up into his soupy end, the ship has foundered from a combination of disease, a submarine that gets caught in its nets and Dench’s rogue wave.

Richard’s novel is a trifle--also in the English sense of the word--that is, a dessert made up of implausibly assorted fruity elements and a hefty dose of spirits. The fumes occasionally overpower it, and the author’s heady images stagger grandiosely.

The stories that the various members of the crew tell, or have told about them, reverberate at times with pretentious psychedelics. There is, for example, the smallpox cook’s tedious account of his feud with a one-armed brother. It ranges from the Far North to the South Seas, and its hallucinatory ins and outs read like a particularly laborious recipe from the magical-realist cookbook.

But for much of the time, “Fishboy” moves with an invigorating cheerfulness. For all their oddities, the crew members are purposeful. Each in his own way is a wrong-headed Paul Bunyan. When the Coast Guard vessel pursues them and picks up the dead sheriff they have jettisoned, Lonny insists that he died of an illness. Why is he disemboweled and his throat slit, the boarding officer wants to know. “Lonny said it had started as a tickle in his throat and an ache,” Fishboy reports.

In fact, despite his ghostly soup condition, his Faulknerian grotesqueries, his LSD hues, there is something downright plucky and resourceful about the young narrator. He is an altered-state Huck Finn. What he lacks is a river.

With all the echoes--Melville, Coleridge, Faulkner, Twain and here and there a touch of Dylan Thomas--Richard has written an essentially literary adventure. His hero floats feistily, but on a book not a raft.