"We'll have to stick to the channel," John Barth wrote in his first novel, "The Floating Opera," and let the creeks and coves go by." His new work ["Sabbatical"] explores all the creeks and coves it can, both literally and figuratively. It drifts with what one of its characters calls the narrative tide, it goes back, goes forward, stands still. It begins with a storm at sea, describes an uncanny island not to be found on any chart and records the surfacing of a hefty sea monster in Chesapeake Bay. "Have we sailed out of James Michener," the narrator wonders, "into Jules Verne?"

The metaphors, as Barth said of his earlier use of them, are not gratuitous, and that's putting it mildly. "If life is like a voyage," we read in "Sabbatical," "a voyage may be like life." "Not the least of sailing's pleasures, in our opinion, is...