Heian Maru

At over 150 m, the Heian Maru is the largest ship in the lagoon — a prewar NYK passenger liner converted into a submarine tender, caught at anchor in the February 1944 raids. Her name remains readable on the bow in both Latin and Japanese characters, a detail that stops most divers mid-fin-kick. Because she rests on her side, swimming her length feels like flying along a steel cliff: propellers, promenade windows, and holds where spare periscopes and torpedo bodies lie racked in the dark. Her scale means most visitors take two dives to feel they have seen her at all.

您此行的高光时刻: The lettered bow; periscopes and torpedoes in the holds; the sheer scale of a liner-sized hull on its side.

地形地貌: Hull on its port side across the lagoon floor at about 34 m

入水方式: Moored dive; orientation matters — the ship lies on her port side, so decks read as walls.

危险因素: Sideways orientation disorients inside; long swim distances for the air supply; torpedo warheads and ordnance remain in the holds.

保育: Widely treated as a war grave — crew died in the attacks. Dive her as a memorial: nothing lifted, nothing rearranged, remains untouched.

高氧（Nitrox）: 在此值得使用——各潜点深度落在富氧空气（nitrox）能有效延长免减压时间的区间（前提是持有相应认证）。