The four most visited Hawaiian islands Oahu, Maui, Kauai, and the Big Island have plenty of diving spots and attractions. If you are interested in some unique dives in less touristy areas, you might need to rent a dive boat. One of the most well known diving attractions is the Sea Tiger wreck In Honolulu. This former Chinese trading vessel is at a depth of nearly 30 meters and is perfect for experienced divers. Lanai is also famous for its diving attractions: swim throughs, archways, and caves. And, of course, don't miss First Cathedral. This is a huge underwater cavern, consisting of tunnels, ridges, and passageways. Since it has a large hole in the top, on a sunny day, rays of light create a marvelous effect inside the cavern. Weather conditions are most favourable for diving from May to September.