Do consider the Big Island as well. It's known for it's coral reefs, great viz and fish life. Currents are few and far between and the bulk of the diving is generally in 35-40 feet of water, with multi-level diving available for divers of all skill levels. My guess is that nearly all the dive ops in the state are pretty used to working with divers of all skill levels, new or infrequent divers are VERY common on all the islands.