ATM's are available on most of the islands, they don't have them in the shops just at banks. If bringing US bring smaller denomination bills, only banks will accept $100's, most other places won't. Bills should be in good shape, no tears, writing or excessive wear. Banks will give you the proper rate of 2.68, bring ID and be prepared to stand in line, the street rate is 2.5, change will always be in EC. Most restaurants will accept credit cards. We usually tip boat boys 10-20 EC for tying a stern line ashore and such. Tipping is 10% if not already included in the bill for restaurants.