A rusty medical box, the embossed cross still visible on the front, sits atop the superstructure, now filled with a mismatched collection of bottles. We drop over the side and descend past the peeling layers of rust until we spot the inviting darkness of an open doorway. Gently cruising into the gloom, our torchlight catches on a rectangular frame.

On closer inspection, we realise we’ve found the sick bay. An autoclave full of silt rests in the corner and a precariously perched drawer contains glass syringes, now yellowed, broken and dusty. The operating table, topped with a neatly stacked pile of bones serves as a disturbing reminder of those that died when this ship went down. More disconcerting perhaps is the knowledge that the deaths occurred in another part of the ship and the bones have later been relocated for photographic purposes.

For most, Truk Lagoon is the ultimate wreck diving hotspot, a once in a lifetime destination and the pinnacle of their wreck diving aspirations. Truk virgins may assume that the diving will be something similar to Scapa, just with warm, clear water and more fish. They are at least partly correct. With temperatures around 28^oC year round and viz ranging from 10 to 30 metres, it is very comfortable diving.

Some wrecks are so densely encrusted with coral that you can hardly make out the ship beneath and what features are visible may be obscured by clouds of fusiliers darting around in a blur of blue and gold. Jacks, barracuda and sharks also make frequent appearances, cruising around in the blue or buzzing past as you ascend the line.

There are however no battleships in Truk. In fact, there are only two diveable warships, both destroyers. The big draw, and what you will spend most of your time diving, is the cargo ships. With minimal salvage and strict ‘no take’ rules, the contents are largely intact and there are artefacts scattered everywhere. It’s this that makes Truk stand out as the premier wreck diving location and it’s the reason so many of us make the arduous pilgrimage to this remote cluster of islands, to see the wonder for ourselves.

As wartime wrecks, the first thing most divers expect to see are weapons. Two depth charges and their associated launchers perch on the port side of the destroyer, Fumitsuki, with shell casings lying on the sand below. Rail tracks wind around the deck, once used for moving torpedoes to the launchers. Further forward you’ll find one such launcher, a sizeable triple barrelled affair that fired the 9m Long Lance torpedoes that you’ll see elsewhere. On the cargo ships, you’ll see deck mounted machine guns, 6 inch bow guns and artillery guns. Some of these weapons, like the wheeled field cannon on the bow of the Seiko Maru, were already obsolete before the start of the war and were used primarily as a decoration to boost morale.

Vehicles are another popular target and the holds of these wrecks do not disappoint. The Hoki Maru carried a construction battalion, most likely destined for runway building. Drop down past the huge curved blade of the bulldozer and the tell tale cylindrical drum of the pavement roller and you’ll find a neat row of well preserved pick up trucks, ripe for exploration. On the Fujikawa Maru you’ll find numerous zero fighters. Among the mess of wings, engines, propellers and cockpits, there are a few aircraft still largely intact. Elsewhere you may see a tank or two or even some bicycles, clearly the war time chariots of choice.

Given the remote location, the Japanese had to import all of their food, water and equipment. You’ll see essentials such as water tanks, pressure cookers and mess kits, however a surprising amount of their limited space was dedicated to beer. Bottles can be found on most of the wrecks but some, like the Rio de Janeiro Maru, have whole cargo holds full of them, still neatly packed in the remains of their wooden crates.

Then there are the wrecks themselves. Several have intact superstructures so you may be able to explore the bridge to see the helm and telegraphs or penetrate the captain’s quarters. There are ballrooms with panoramic windows, the supporting columns for the ceiling now twisted and warped; dining rooms with the metal bases of tables sprouting from the floor; and even a galley complete with stove, extractor fan and pots scattered on the counter.

The anthropomorphic air compressor known as R2D2 can be found deep inside the machine shop of the Fujikawa Maru. Exploring further, you’ll find a perfectly preserved drill press and lathe along with cage light bulbs and fans neatly organised on the shelves of the adjacent store room.

The engine rooms are a firm favourite and with several levels of intact machinery, in depth penetrations are the norm. Enter the torpedo hole on the Shinkoku Maru and make your way past the uniform row of generators. Gradually work your way up the narrow metal stairs, around cylinder heads and along catwalks to the skylights above. Elsewhere, the gigantic spanners may make you wonder how many men it would take to successfully tighten a nut. One engineer even died at his station and you can still see his skull fused into the metal.

As the curators of this underwater museum, the dive guides polish algal growth from plaques and painstakingly reassemble broken ceramics and pieces of gas masks. They guide visitors through the complex maze of machinery and wreckage pointing out the stacks of periscopes, jumbled heaps of torpedoes and the particular features that make each wreck unique. These ships and their cargo give visitors an unparalleled insight into Japanese Naval life. By preserving these exhibits, the local dive operators ensure that rust hunting pilgrims from around the world will be enthralled for years to come.

For more from Chris and Maddy visit www.adventureoclock.com

Discover more about DiveQuest diving holidays at www.divequest-diving-holidays.co.uk