Truk Lagoon, now more commonly called Chuuk Lagoon, is an underwater museum of ships and aircraft sunk during Operation Hailstone in 1944. Coral growth, schools of fish, turtles and reef sharks now surround structures that still contain vehicles, aircraft parts and personal artefacts.

The wrecks cover a very wide depth range. Some can be enjoyed from the exterior by suitably experienced recreational divers, while the deepest ships and any serious penetration require advanced wreck, decompression or rebreather training. Divers should not assume that one certification opens the whole lagoon: the correct boat, guide, gas and plan depend on the wreck selected.

A liveaboard makes it possible to move efficiently between wrecks and schedule early dives before other groups arrive. It also supports repetitive diving with suitable gas choices and allows deeper profiles to be balanced with shallower wrecks. Night dives may be offered on an appropriate wreck or reef, but penetration after dark should never be treated casually.

The U.S. Naval History and Heritage Command account of Operation Hailstone adds historical context to the wrecks. They should be treated as historic and, in some cases, sensitive sites; artefacts and human remains must be left undisturbed.

Compare Truk with Bikini Atoll. Bikini’s fleet is generally deeper and more technically demanding, while Truk offers a broader range of ships and profiles within a sheltered lagoon.