Mahi Wreck

The Mahi, a 185-foot former minesweeper, rests in 95 feet of water off Waianae's coast, creating one of Oahu's most accessible artificial reefs. Sunk intentionally in 1982, this WWII-era vessel now hosts schools of white spotted toboies, eagle rays, and green sea turtles that cruise through the wheelhouse and cargo holds. Advanced open water divers find the Mahi perfect for their skill level. The wreck sits upright and intact, with multiple swim-through opportunities including the engine room and bridge. Visibility typically ranges from 80 to 150 feet, making photography rewarding. The ship's structure creates shelter from currents, though northwest swells from October through March can make surface conditions choppy. Charter boats depart from Waianae Harbor, with most operators offering two-tank dives that include the Mahi and a nearby reef site. Expect to pay around $130 for boat dives. Bring your own gear or rent from dive shops in town. April through September provides the calmest conditions, though the site remains diveable year-round. Park at Waianae Boat Harbor for $5 per day. The harbor fills up quickly on weekends, so arrive by 7 AM for popular charter departures. Most dive operations leave between 7 and 8 AM to take advantage of morning calm before afternoon trade winds pick up. Strong swimmers comfortable with deeper water should attempt this dive. The wreck's depth means shorter bottom times, typically 20 to 25 minutes depending on air consumption. Currents rarely present problems, but always follow your dive guide's briefing about entry and exit procedures around the vessel's superstructure.