The Legend of Zelda: The Wind Waker Guide Islands of the Great Sea
Star Island (B1)
Star Island is quite small and, like other islands, gets its name from the way it looks from above. It offers only a few activities for you.
Sea Platform
Sail to the single Sea Platform and climb its ladder. A chest atop the Sea Platform contains a minor reward.
Blue ChuChu
Defeat the Blue ChuChu underneath the large southwest boulder for a Blue Chu Jelly. (Bomb the large boulder to expose the Blue ChuChu.)
Silver Rupee (via Treasure Chart #7)
Finding and opening Treasure Chart #7 (found at Windfall Island [D2]) allows you to pull a chest containing a Silver Rupee up from the Great Sea near Star Island.
Piece of Heart #27 (via Secret Cave)
Bomb the large boulder on the island’s west side to reveal a hole leading to a Secret Cave. Defeat all enemies here to reveal a chest containing Piece of Heart #27.