The local currency is guilders, but the U.S. dollar is accepted throughout Bonaire. The exchange rate is fixed at 1.77 guilders to the dollar. Credit cards are widely accepted. Some restaurants will add a 10 percent service charge. Read the check carefully before tipping.
Converters are available in the hotels.
Many dive shops have adapters for charging sensitive photo gear. Distilled and purified seawater from the tap is safe to drink. A passport is best, though a birth certificate and photo ID will suffice. You'll also need a return ticket. So many dive sites, so little time.