As a pirate, you will always have competition from others pursuing the same treasures as you! Win the chest in the Daily Cup and the treasures will be all yours. To do this you will first have to enter the Daily Cup by selecting the trophy icon in the top left-hand side of your map screen. 

How well you do in a race will determine how many trophies you receive for it. All the trophies you collect will go towards opening the two chests. You will be able to re-race you opponents periodically but only have 24 hours to claim your prize before the next Daily Cup commences.