The unfinished land / Greg Bear.

Enhanced descriptions from Syndetics:

A sweeping Elizabethan historical fantasy from an internationally renowned author that evokes the seafaring adventures of Robert Louis Stevenson and the magic of The Bear and the Nightingale

Reynard, a young apprentice, seeks release from the drudgery of working for his fisherman uncle in the English village of Southwold. His rare days off lead him to strange encounters--not just with press gangs hoping to fill English ships to fight the coming Spanish Armada, but with strangers who seem to know him, one of whom casts a peculiar shadow.

The village's ships are commandeered, and after a fierce battle at sea, Reynard finds himself the sole survivor of his uncle's devastated boat. For days he drifts, starving and dying of thirst, until he is rescued by a galleon, also lost--and both are propelled by a strange current to an unknown northern island. Here, Reynard must meet his destiny in a violent clash between humans and gods.