Guide to 26 of O`ahu's (Hawaii) best snorkeling and diving sites. Includes detailed driving directions to each location as well as maps showing onshore facilities and many interesting offshore features to explore. Describes the safest spots to enter and exit the water, what to look for (coral, shells, fishes, underwater caverns), and hazards to avoid. Provides essential information on safety and seasonal wind and surf conditions and tips on diving and snorkeling equipment, night diving, and spear fishing. Each site is rated according to degree of difficulty.