I have been using Dive Adventurers ( www.stmaartendive.com )out of Simpson Bay Resort and Marina for the last 20 years. Have over 280 dives with them. Wouldn't think of using another dive operation in St Maarten. They will take you to all the better dives sites like Proselyte, Carib Cargo, Moon Hole, Groupers, The Maize, Fish Bowl, Cable Reef and others along with a new recently sunken boat I hope to dive this May.