Treasure hunt

You are in service of the King of Spain. Your job is to find treasure chests. Every time you find a treasure chest, he will reward you. He will choose the reward. No treasure chest will be easy to find. The problem with finding a treasure chest is what's making it difficult for you to find them, they are usually pirates, sometimes other treasure chest hunters. Locals who live within the areas you're searching might either be sympathetic to you or pretend to be loyal only to mislead you or inform the owners of a treasure chest of your searching for the chests.