Viator by Lucius Shepard

After being run aground, the rusting hulk of Viator lies amid trees and boulders in Alaska. A mysterious employer has hired five men to watch over Viator and prepare her for salvage operations. Little work appears to get accomplished, yet the employer doesn't seem to care or notice. The crew instead get sidetracked into monomaniacal activities and slip further and further away from the real world. Is Viator undertaking one last voyage to a destination not found on any earthly map? It would seem so, and Shepard deftly builds and builds tension and madness as the story goes on.
And then the protagonist wakes up and finds it was all a dream. Okay, not exactly, but still a very disappointing anticlimax. My advice: read all but the last ten (10) pages and make up your own ending.