Use boat to circumvent this island
The party enters the boat and rides along its beaches. Sailing counter clockwise from the landing point you see a small fishing camp, a medium sized village, and an ancient abandoned sea port on the islands north most point.
As you travel back around to the landing point you see that the very ship you escaped from is anchored not far off shore, but you see no activity on the ships deck. on the South eastern portion of the island you see a small camp made by the Mutineers. The Mutineers see you and one runs out of the camp and into the forest while the other three watch as you sail past them.
Night has fallen by the time you return to the landing point. based on this the party reasons that the island is fairly large but could not take more than a day to walk across.