Kogyo Maru

The ship is on her starboard side, so the first thing to adjust is what counts as up. The top deck stands vertical, close to a wall dive, and the front mast runs out horizontally into the blue with its crow's nest at the end of it. The cargo-hold openings in that wall are big enough to swim into without ducking.

The second hold is why people come. Cement bags tumbled into a slope as she went down and set into the shape of the sacks that held them, and a small bulldozer sits complete and encrusted at the bottom of the incline. It holds your attention long enough that the operators here have to warn divers to look up: a tractor and an air compressor are perched above the cement, and the divers who fixate on the bulldozer swim out without seeing them. Through a hole in the bulkhead is the next hold, with more cement and coils of rolled wire mesh meant for a runway that never got built.

Past the holds the route runs to the bridge and then down into the engine room beneath it, usually entered from the stern end. The galley is in two halves, split by damage, with a rice cooker and a stove still in one of them. Most of this is lit. There are open hold entries with daylight coming through and the way out in sight, which is unusual for a wreck of this depth and is the main reason the site has the reputation it has.

Then the barracuda. A school works the water off the hull, and the standing local advice is to keep your eyes moving, because divers who spend the whole dive looking at cargo miss the only pelagic event the site offers.

Every other Coron wreck tells you how the fleet ended. This one tells you what it was doing. She was carrying the machinery to build an airstrip on a tropical island, and the plant is still in her holds where gravity dropped it: a bulldozer you can picture someone driving, a tractor, a compressor, sacks of cement turned to stone.

She is also the wreck that broke the tape measure. A photogrammetric survey in 2025 measured her hull at 157 metres, against records that put her between 128 and 135 as built. The surveyor checked the Lloyd's of London register, found an entry of about 420 feet, and reported that the entry was crossed out. Rather than pick the number that fitted, he published the conflict1. Nobody has resolved a discrepancy of a fifth of a ship, which makes this the rare dive site where the honest thing to say about the basic dimensions is that the question is open.

And the penetrations here are the good kind. Big lit holds where the exit stays in view are a different experience from a dark corridor, and this is the Coron wreck where a diver can find out which one they actually enjoy without finding out the hard way.

She started as an ordinary merchant cargo ship of 6,353 gross tons, built at the Uraga Dock Company for an Osaka owner, and the Imperial Japanese Navy requisitioned her in August 1941 and converted her into an auxiliary transport. Two records-based accounts of her building disagree by eleven years while agreeing on the yard, the owner and the tonnage, so this page carries no build year.

In late August 1944 she loaded at Takao with passengers and with construction plant: tractors, bulldozers, carryalls, trucks, generators, compressors, the machinery an airfield takes. She reached Manila Bay on 19 September and came through the raid there undamaged, then left on the 22nd with the convoy running for Coron.

She dropped anchor in Coron Bay at twenty to four in the afternoon on 23 September, and her crew spent that night trying to camouflage the bridge and the main deck2. The fleet had come here on the belief that Coron lay beyond the range of American carriers. It did not. Aircraft found the anchorage the following morning, she took several bomb hits and went down on her starboard side with the airfield still in her holds. She is one of six Coron wrecks whose photogrammetric scale models were handed to the National Museum of the Philippines in February 20263.

Look at the cargo and touch none of it. The bulldozer and the tractor are lying mangled on an incline of cement bags that formed while the ship was sinking, and no one can tell you whether that pile is done moving. Everything on and in this hull is also state-owned cultural property under Republic Act No. 10066, so the hand tools and machinery parts that make this wreck collectable are the exact things that must stay4. Identify them, photograph them, leave them.

Wear a full-length suit. Stinging hydroids grow on the hatch openings, which are precisely where an unwary diver puts a hand on the way through, and there is torn metal in the galley area where the structure gave way.

Look at the entrance before you commit to anything. Most of this ship's penetrations are open and lit with the exit visible, and that is a genuinely different activity from a dark route with turns in it. Being able to tell the two apart is worth more here than any amount of reassurance on the boat, and the difference has caught out divers on this fleet within a single day.

Let your gas plan the route, not the briefing. The published route for this wreck branches on remaining air, which is the right way to run a 36 metre dive with six holds, an engine room and a bridge to choose from. Nitrox extends the useful part of it where a shop stocks it. And settle the evacuation question before you book, because no working recompression chamber is confirmed anywhere in Coron.