THE FISHERMEN written and directed by Dianne Houston; scenery by Tom Loftis, costumes by Monifa Christian.

With Phyllis L. Baker, Dwania Kyles, Andre Robinson, Barry Wiggins and Fred Strother.

At the New Back Alley Theatre, 1365 Kennedy St. NW, through May 4.

During the first act-and-a-half of "The Fishermen," Washington playwright Dianne Houston nimbly introduces us to a believable group of characters and a potent situation. Then she takes these promising beginnings and drowns them in a Sargasso Sea of pontification and pretension.

Houston's play is about a traditionalist black minister, his loyal wife and their uncertain, vaguely rebellious son. The Rev. Milton Tyler is up for a city council appointment, but so is his militant nemesis, the Rev. Akbara. He and Akbara "go back a long way," Tyler recalls. "He was full of crap then. He's more full of crap now."

But Tyler's son Jeremy and his friend Lee have been working at Akbara's "Church of the People." Lee (who is changing his name to Abdullah Ben Kahim) dismisses Tyler's church as "just a bunch of Toms."

So far, "The Fishermen" may be a little slow-moving, but it is moving in a sensible direction. Then the oratory and the symbolism move in. One character dreams of being a "lighthouse," and another declares that she is, at heart, an "eagle." Rev. Tyler, for his part, plucks an old war memento -- a grenade -- from its box, begins fondling it, and launches into a mind-numbing reminiscence about war, courage, friendship, love, you name it.

There are vague intimations of homosexuality here. Playwrights love vague intimations of homosexuality.

Then a hostage situation develops -- inspired, apparently, by the Hanafi Muslim siege in Washington three years ago. The police kill Akbara, issuing a phony explanation of his death. And Lee, in revenge, takes a small arsenal of weapons down to City Hall, seizes an employe and threatens to kill her. Jeremy rushes to Lee's rescue. It ends tragically.

The New Back Alley Theatre has assembled a skilled cast for Houston's play. Phyllis L. Baker has several powerful speeches as the mother, and Barry Wiggins is natural and unaffected as Lee. And while Dwania Kyles, as the crippled but acid-tongued Mamma E, has to resort to some extreme cosmetic measures to look sufficiently old, she is effective and funny just the same.

But "The Fishermen" is unworthy of these actors' talents -- and of the author's. Houston has a sharp ear and a serious mind. She has to decide if she wants to be a preacher or a playwright. There's a difference.