Okikawa Maru

Ten metres down, the top of the deck arrives in full daylight and it is not obviously a ship. Soft and hard coral cover the plating end to end, and the first impression most divers describe is a reef that happens to have a shape. Then the scale registers. This is a hull of about 160 metres and you swim it lengthwise, deck at 10 to 16 metres, with the sand a long way below at 261.

The stern is where the dive concentrates. Snapper and batfish stack up behind the huge rudder, out of the current, and the current is the reason they are there. The propellers are missing from the shafts. The bow at the other end is broken away from the ship and sits nose upward, which gives the swim a beginning and an end.

There is a decision at the stern. The signature interior route goes into the propeller shaft and through to the engine room, and the empty oil tanks are the other way in. Both are genuine overhead. Inside is dark and narrow, in a way the bright deck outside gives no warning of.

The exterior dive is not a consolation prize and should not be sold as one. It is the longest bottom time available on any big wreck here, on a deck shallow enough to spend an hour over, and the reason a diver who lives in Coron and has thousands of dives names this wreck as a favourite over any of the deep ones.

Two divers with nothing in common book the same site. One has twenty dives and has never seen a ship underwater, and gets the whole of this one: the deck in the light, the rudder, the schooling fish, an hour of it. The other has a wreck certification, a torch and a reel, and comes for a shaft entry into an engine room. Neither is getting the lesser version.

The coral is what separates her from the rest of the fleet. Every other big Coron hull is a ship first; this one has been colonised so thoroughly that it reads as structure, and at 10 metres in daylight the colour is real and not something a torch has to find. Nudibranchs all over the plating turn a 160 metre tanker into a macro dive, which is a strange sentence and an accurate one.

She also carries the best story in the bay. The wreck was dived as the Taiei Maru for over fifty years, the name changed to Okikawa Maru, and the naval record has never fully closed the question.

She was a wartime standard tanker of 10,043 gross tons, a mass-production merchant hull requisitioned as a navy auxiliary oiler. She was not a warship. Her length is recorded at just over 160 metres, which makes her the longest hull dived at Coron, though the figures printed on shop boards run as high as 176 and cannot all be right.

In September 1944 she was at Manila, and left with the convoy that reached Coron Bay on the 23rd and anchored near the town of Concepcion. American carrier aircraft found the anchorage the next morning. Fighter-bombers strafed her first; a bomb hit landed portside aft at 0910, and at 0918 more hits went into a boiler room and an engine room. She caught fire and was stranded, her burning forecastle still visible after the attack passed2. A follow-up strike two weeks later finished the hulk, and she settled upright in about 26 metres of water1.

Then the name. Divers dived her as the Taiei Maru for over fifty years, until a reassessment of the wreck's position and physical characteristics moved the identification to Okikawa Maru, which is the name every operator now uses. The record has not caught up with the consensus. The compilers of her service record publish a standing reservation against their own page: a Japanese convoy history lists a Taiei Maru of a different standard tanker type in that convoy and does not list the Okikawa Maru at all, and a photograph taken before the strike shows a tanker of that other type further east2. The same compilation carries a second complete service record, under the rival name, describing the same attack, the same bomb hits and the same sinking position1. Two records, one hull, and no verdict.

She is one of six Coron wrecks whose photogrammetric scale models were handed to the National Museum of the Philippines in February 20263, so the state is now recording in three dimensions a ship whose name it cannot confirm.

The tide decides this dive. She sits outside Coron Bay in open water and the current runs hard, hardest around the stern, so the boat picks the window and you dive it when the water allows. Carry an SMB. Start into the current. Finishing against it is the mistake.

Be specific about what going inside means before the boat leaves. Entry here is supposed to require a wreck specialty, and divers report that the requirement is not applied consistently. The failure mode is documented on this exact wreck: a swim-through agreed to on deck, and then over ten minutes of complete darkness in narrow passages with hoses snagging. Ask to see the entrance. Reserve the right to look at it and say no. If you do go in, carry a torch and a second one, and set a separate turn pressure for the interior, because divers come out of this hull having used far more gas than they planned.

Nothing leaves this ship. She passed fifty years old, which makes everything on and in her state-owned cultural property under Republic Act No. 10066, and disturbing the site requires written authority and museum supervision4. The propellers are already gone and nobody has explained where they went.

Plan the day around the crossing. This is the furthest of the routinely dived hulls from Coron Town, roughly half an hour by boat even from the nearest resort base, and no working recompression chamber is confirmed anywhere in Coron. Hold insurance that pays for hyperbaric treatment and for an evacuation flight, and check the boat carries oxygen before you get on it.