Aikoku Maru (1940)

A cruiser lost in a single blast. The Aikoku Maru was a large Japanese armed merchant cruiser that met a violent end during the 1944 raid on Truk Lagoon, when a bomb detonated her munitions and blew apart her forward section. She rests upright on the lagoon floor, her shattered bow a stark record of the explosion that killed most of those aboard.

A deep, sombre wreck. Much of the ship lies beyond recreational limits, with the deeper structure reaching around 60 metres. The intact stern, superstructure and engine spaces make her a serious technical wreck, and any meaningful exploration of the depths demands trimix, staged decompression and appropriate certification rather than a standard recreational profile.

Cargo and quiet interiors. Where divers can reach her, the holds hold trucks, machinery and the scattered remnants of a warship's stores, all encrusted after decades underwater. The scale of the vessel and the abruptness of her loss give the site a solemn, war-grave atmosphere that operators treat with respect.

Coral over tragedy. Soft corals and reef fish now cloak the standing structure, and visibility in the sheltered lagoon is usually good. The Aikoku is one for experienced and technical divers within Chuuk's wider fleet, dived year-round with the calmest, clearest water generally arriving in the northern winter and spring.