Most Caribbean islands accept a form of local dollar, while some will also take US dollars and one or two accept euro. If you're hoping to bring home a Caribbean souvenir or buy a drink while in port, these are the currencies you'll need for each island:
Antigua & Barbuda - East Caribbean Dollar (XCD), Aruba - Aruban florin (AWG), The Bahamas - Bahamian dollar (BSD), (US dollars widely accepted), Barbados - Barbadian dollar (BBD), Belize - Belize dollar (BZD), Bonaire - USD, British Virgin Islands - USD, Curacao - Netherlands Antillean guilder (ANG), Dominica - East Caribbean Dollar (XCD), Grenada - East Caribbean Dollar (XCD), Guadeloupe - Euro (although US Dollars can be used), Honduras - Lempira (HNL), Martinique - Euro (although US Dollars can be used), Puerto Rico - USD, Saint Kitts & Nevis - East Caribbean Dollar (XCD), Saint Lucia - East Caribbean Dollar (XCD), St Martin - Euro (although US Dollars can be used unofficially), Saint Vincent - East Caribbean Dollar (XCD), Trinidad & Tobago - Trinidad & Tobago Dollar, Turks & Caicos Islands - USD, US Virgin Islands - USD