Hellhole, it sounds like you dove the Oakita Maru, aka Tapilon. It is a WWII cargo carrier located close to the mainland, quite broken up but still can be an interesting dive. It is not difficult to locate a few 2-3 inch artillery shells at that site. Depth is 22-28 meters.
The passenger ferry Dona Marilyn went down much more recently, in 1988 during a typhoon. Located past Gato island, it is very much intact and a great dive. Weather conditions need to be fairly calm to get out to this site. There is plenty to see on the outside of the wreck, and it provides a number of options for penetration. However, most dive operators on Malapascua will not allow penetration without proper training. Depth on this site is 18-32 meters.
Nitrox is recommended on both of these sites, bottom times are a bit short on air.
There are two other known wrecks around Malapascua. There is a WWII landing craft known as the lighthouse wreck which is in very shallow water close to Malapascua. It is very broken up, and mostly visited for training dives. The Mogami Maru, aka the Pioneer, is a smaller WWII wreck that is fairly intact and not usually visited due to the depths of around 45-50 meters. It is however a good dive for those who are qualified.