Nippo Maru

A working freighter built in 1936, the Nippo Maru spent the war hauling the unglamorous freight that garrisons live on — above all fresh water for Truk's outer-island gun crews, along with munitions and equipment. Hailstone's bombers sent her down in February 1944, and she landed upright with a gentle list on a deeper patch of lagoon floor, which kept casual visitors away for decades and preserved her details. What survived is a museum spread: a Type 95 light tank sits on her deck as if parked, field artillery pieces lean nearby, trucks and mines occupy the holds, and her compact bridge still holds its helm and engine telegraphs — one of the most photographed compositions in wreck diving. She was lost to memory after the war and relocated by divers in 1980. The depth that protected her also demands respect; this is the lagoon's threshold wreck between sport and technical diving, and a war grave besides.

How she sank: Bombed by US carrier aircraft during Operation Hailstone, February 1944.

Condition: Intact and finely detailed, with slower growth and dimmer light than the shallow wrecks; corrosion is gradual at this depth.

Penetration: Limited. The bridge and forward holds admit trained divers for short, shallow-in penetrations; anything deeper in the hull is technical territory. Entering any overhead environment requires specific training — a wreck certification at minimum, technical wreck training for full penetration.

Recommended certification: Deep-trained Advanced Open Water; technical certification recommended for full exploration

Current: Mild · Visibility: 15–30 m

Marine life: Whip corals and black corals at depth, lionfish on the bridge wings, and batfish escorting divers along the deck.

Hazards: Depth and bottom time are the governing risks; munitions in the holds are untouchable; silt lies thick on every horizontal surface.

Chuuk lagoon monument protection; state dive permit/fee applies.

Treated as a war grave with the rest of the Hailstone fleet; conduct yourself accordingly.

The tank, guns, and bridge instruments stay where the war left them — removal is illegal.