The used currency is dollar E.C. (Dollar East Caribbean), whose exchange rate is linked to dollar US: 1 $US = 2.65 dollars EC.
The $US is accepted with any problems. The travellers checks in Euros are not accepted; only dollars or pounds. Most of banks open from Monday to Thursday from 9h to 15h and Friday from 9h to 16h. You will find cash dispensers which work for Visa, American express, Diners Club, MasterCard anywhere in the island but not all of them does accept all kind of cards; for more safety, we advise you to go to Saint-John’s distributors.