Briley, John M: Seafoam Wavefollower and the Mysterious Ghost

Seafoam Wavefollower, a juvenile sperm whale and skilled navigator, gets himself trapped in a sea cave under Mowie. Before the "Twenty-Four Hour Rule" forces his family to abandon him, Seafoam is forced to rely on the ghost of a mysterious Hawaiian boy he doesn't trust to lead him the way out via an underground river. Warriors, sorcerers, and a giant whirlpool (among other traps) bounce him from one fine mess to another. Time is running out...