The Legend of Zelda: The Wind Waker -
The two treasure chests contain Treasure Chart #43 and a Golden Feather. Treasure Chart #43 corresponds to a sunken treasure located just to the east, over at Outset Island. This is one of many sunken treasure that we can collect as we head towards the northwest corner of the Great Sea. Most notably at the far western portion of the Great Sea at Three-Eye Reef, Link can salvage the sunken treasure from Treasure Chart #32, which contains Piece of Heart #28. This is one of the treasure charts won at the auction, so you may have yet to get this from Windfall Island. Also at Three-Eye Reef, there are five shiny locations just southeast of the island where Link can salvage five treasures, each containing a Purple Rupee.