It’s not just about the sharks eating the spoils from a fading fisherman’s last great hurrah. It’s about what happens to the old man himself after he returns to shore, how his surrogate son is affected and what we think of obsession, aging and manhood. This reconsideration gives an added dramatic layer to Hemingway’s allegorical tale but it’s still not enough to color in these slender, symbolic characters.

The first act is expertly crafted by co-adapters Eric Ting and Craig Siebels, who respectively helmed the production and designed the handsome wood set. Things get right down to business with the Old Man (Mateo Gomez) quickly casting off to sea and hooking the great fish, leaving an audience to think this adaptation of the short novel will be over in no time.

The character of an adoring and adorable Boy (Rey Lucas) is on hand to offer helpful background narration supplied in third person by Hemingway in the novella. The Old Man also helps in the storytelling, conveniently talking to himself while sailing solo, offering insights into the specifics of fishing on a skiff — as well as the character’s singular state of mind.

A third character, Cienfuegos (Leajato Amara Robinson), provides moody musical accompaniment on guitar and later appears in a brief flashback as an arm-wrestling challenger when the Old Man was in his prime.

Most of the first act takes place on the boat and while occasionally engaging, inventively staged and authentically acted, the narrative has its limits. At act’s end, the Old Man lands the fish — but as anyone who took a high school English class knows, he’s still in for a helluva trip back.

The second act opens with the Old Man already at his shack of a home, in his single bed, ravaged by memories of his dream catch turning into his worst nightmare. The Boy quickly brings the audience up to speed about sharks devouring the fisherman’s prize and the Old Man’s excruciating, exhaustive and Calvary-like slog home. (Ting and Siebels also nicely weave narrative from the early part of the novella they had previously skipped over.)

Instead of the open sea the Old Man is faced with a mind gone mad, reliving his horror not from his boat but from his bed.

As his hero falls from grace into dementia, the Boy finds his manhood, not through feats of machismo, but in the role of tender, dutiful and loving caregiver. The Boy’s humanity is a value that even the Old Man — whose life is a battle with Nature — must recognize.

It’s a clever conceit, honoring the Hemingway tale while commenting indirectly on issues of identity, masculinity and duty. But just as in the book, the characters remain principally symbols, sketchily drawn with little history or individuality, so our hearts only go out to the water’s edge.

Production is elevated by Michael Chybowski’s lighting and John Gromada’s sound and music, which beautifully evoke the vast gulf as well as a mind at sea. Gomez gives a richly varied, passionate and leonine perf as the Old Man. But Lucas’ commanding storytelling, depth of sensitivity and growth of character as the Boy shows that this is as much his character’s story — something that might have even escaped the man and writer they called Papa.

Sets, Siebels; costumes, Kay M. Voyce; lighting, Michael Chybowski; sound, John Gromada; production stage manager, Charles M. Turner III. Opened, reviewed April 8, 2009. Runs through April 26. Running time: 1 HOUR, 50 MIN.