AP Oakita Maru

This wreck, just off Malapascua, is variously called the 'Pioneer' (it isn't) and the 'Unknown Maru'. Terry Dukes found a reference to a Japanese Personnel Carrier, 'AP Oakita Maru' sunk on 12th September 1944 at coordinates close to the wreck site (N 11-21; E 124-07 reference The Official Chronology of the US Navy in World War II). There were many ships sunk that day by US Task Force 38, and this is the only one at Malapascua, and close (within 1 km) of the wreck site at that. The designation 'AP' is US terminology for Auxiliary Personnel, that is, a personnel transport ship. Many of these ships were converted from existing vessels. The Queen Mary (83,000 tons) was one, and fishing trawlers were also pressed into service, so there is no standard plan for the type, for there is no type. All we know is that Terry has measured the width  of the ship at about 8 metres. There's a good rule-of-thumb for calculating ship tonnage:-

length * breadth *draft / 3 (in metres) = displacement tonnage

Merchant ships' relative dimensions vary, however, such a width indicates a ship of about 500 tons.

I've only dived it once, but in the stunning 25 metre visibility I tried to put together a rough plan, and what it might have looked like. The bows are intact although the deck has rotted through. In the level below the deck is a hatch leading deeper. I'd like to look in there one day. Moving aft there is the broken mast and a hold. Behind this, the deck steps up a level and a winch marks the edge of a debris field where Terry found the ship's brass binnacle. Behind this is a long brass rod which would have been the telegraph control to the engine at the stern. That the heavy brass binnacle was found at the for'ard end of the debris field suggests that the bridge was located right above. The stern has been badly bombed, and the big stern mounted diesel engine is barely visible. Moving forwards and under the deck, an auxiliary machine room with a generator can be found.

My mental image of the ship is shown below. Click on the picture to see what the original might have looked like.

AP Oakita Maru 22 nm S of Masbate Is. (11-21N, 124-07E) The Official Chronology of the US Navy in World War II--1944

Perhaps, and it's a big perhaps, the 'Oakita Maru' was a converted trawler like the 'Sapporo Maru' of Truk Lagoon (380 tons below). Certainly, the sketch of the 'Sapporo Maru' has a generic similarity to my sketch above, that incidentally was made before I saw the drawing below. I have not modified my sketch.

The Sapporo Maru (drawing taken from World War II Wrecks of the Truk Lagoon by Dan E. Bailey 2000