During the second world war the atoll of Truk, in the south-west pacific, was the forward base for the Japanese navy. In February 1944 the Americans laid seige to Truk Lagoon, executing a destructive aerial bombardment known as Operation Hailstone. 30 waves of American bombers destroyed 250 Japanese planes, an estimated 60 vessels, and thousands of Japanese and Chuukese. Operation Hailstone set a two-day World War II record of destruction: 180,000 tons of shipping was sunk. Today, dozens of Japanese ships and artifacts can be seen in the clear Lagoon waters.

Diving on these ships captures a historic moment in time. Their guns remain facing the sky, still armed with spent ammunition shells strewn across their decks, and holds are packed full of military hardware and explosives. Truk Lagoon is a 'must' for any discerning wreck diver. The shallowest wrecks lie just a few metres below the surface, while the deepest, the "San Francisco" is at 65m. The average depth for the majority of wrecks is between 30m to 45m, the currents are gentle and visibility is usually very good. Diving is excellent all year round and the best way to dive Truk, or Chuuk as it is also known, is from the liveaboards SS Thorfinn and the Odyssey, or land-based from the very well operations at Truk Blue Lagoon Dive Resort or the Truk Stop Hotel.