The Mahi - Oahu Dive Sites

The Mahi is Oahu's most popular dive site and originally sunk in 1982 as an artificial reef project, it is located 1/2 mile offshore and a 15-minute boat ride from Waianae Boat Harbor. It is believed that the Mahi was originally built as a minesweeper, but the Navy instead used the 800-ton ship in the Bahamas for laying cable. The Dillingham Corporation purchased the vessel in March 1968, and leased it to the University of Hawaii as a research vessel. Although originally sunk facing shoreward, it now lies upright on a sand bottom, facing seaward. In 1982, Hurricane Iwa repositioned the ship 180 degrees to its present bearing. Conditions vary from 50 to 100 feet of visibility, with light to seasonally heavy surge. There are moorings on the bow, amidships, and stern to protect it from anchor damage. It is immediately apparent how successful it has been in attracting marine life. Schools of 20 spiny puffer fish have been spotted in mid water, facing into the current beside the ship's mast. At 60 feet, the wheelhouse provides a great photographic set-up, with a large porthole ringed with snowflake coral, red and yellow encrusting sponge, and hydroids. On the Main Deck, the most insistent of the resident fish are the large school of milletseed Butterflyfish, and ta'ape waiting for handouts. If you don't feed them, they swarm you until either you relent, or another diver enters the scene. (Photo Tip: To keep them out of the setup, take a small mesh bag with fish food and tie it off on the main deck, then do your shoot somewhere else) A couple of Whitetips, named "George" and "Martha" are sometimes spotted here, as well as up to four eagle rays. Sometimes, if you are lucky, you might encounter a whale shark here. Check out the log to see if one has been spotted recently!