We do lots of dives where you get off an (unmoored) boat and are picked up somewhere else, but I wouldn't call most of these "drift dives" because there isn't much current and you have to swim. The only real drift dive I've had in Belize so far was one day at the Aquarium (Lighthouse Reef), where I reckon the current was around 2mph. Not like drift dives I've done in some other places where you tuck your arms and legs in and watch the world rush by.