From publisher blurb:
Explore a chain of islands full of interrelated danger, intrigue, and adventure that can be woven into an entire campaign. Originally published in 1977 for the world's first roleplaying game, this classic setting sourcebook has been adapted specifically for use with Swords & Six-Siders™, the 1d6-based OSR rules.
The map for each island uses a hex overlay, with descriptions of possible encounters provided for each applicable hex. New rules (including travel and ship combat), monsters, and a bonus tenth island are also included.