Nippo Maru

The Nippo Maru is one of Chuuk Lagoon's most photogenic and accessible wrecks — a 108-meter Japanese cargo ship sunk during Operation Hailstone on February 17, 1944, now resting on her port side in 48 meters of water with her upper hull reaching to 29 meters. She is famous for the Type 95 Ha-Go light tank that sits on her upper deck, the perfectly preserved 37mm anti-aircraft gun, and the howitzers that line her deck — one of the richest single concentrations of WWII weaponry still accessible to recreational-adjacent divers. The upper deck is the dive's headline, with the tank, howitzers, and anti-aircraft gun arrayed in spectacular photographic formation at 32 meters. Further exploration reveals the bridge, wireless room, the ship's wheel still in position, and intact cargo holds that contain spare aircraft engines, tractor parts, and shells. The wreck's side-resting position gives dramatic underwater photography angles, with the tank appearing to balance on a vertical surface. Marine life is classic Chuuk. Hard and soft corals encrust the hull, gorgonian fans reach a meter across on the deeper sections, and sponges add color to the steel. Resident giant moray eels, scorpionfish, and lionfish inhabit every crevice, while black-tip reef sharks, barracuda schools, and Napoleon wrasse patrol the wreck. Macro life on the coral growth includes pygmy seahorses, nudibranchs, and the Chuuk specialty — large populations of crown-of-thorns starfish on some sections of the hull. The Nippo Maru is Advanced Open Water diving at the deck, with Technical or Wreck certification recommended for deeper exploration. The 29-meter upper hull is achievable within recreational limits for Advanced Open Water divers with Nitrox. Accessed via Chuuk liveaboards or Weno-based operators, reached by international flights through Guam. Visibility 15-30 meters, water temperatures 28-30°C year-round. Best conditions December through April.