There are no banks or ATMs on the island but there are a couple internet cafes. One across from the main plaza had a sign offering a money exchange service but when we tried to use it, they had no pesos to exchange for dollars. USD are accepted everywhere but at about 10-15% less than the official rate. Credit cards are accepted at larger hotels and a few of the restaurants and stores in town but don’t be surprised if they add on a 5% bank charge to your purchase.
In addition to packing cash and sunscreen, bring along insect repellent as well as the mosquitoes can be a bit fierce at night.