Hi,
been diving in Malapascua in aug 2001, twice on Monad schoals dives site (the place where you spot threshers). each time was fantastic, though the sea was really rough and the viz bad.
First time on an afternoon dive, we saw 6 manta rays flying over us. One was really HUGE, some 4m wingspan.
Second time early 5h30Am dive, we were 3 boats of different dive centres, only mine saw something and what a thing !!! 3 threshers circling at the cleaning station, at closest we were creeping on the bottom some 4 or 5 metres from them, and stayed for 20 minutes, looking into the blue, a devil ray also passed by.
That morning when we went up to the boat, the anchor chased we had to cut the line, there were waves more than 2 meters high and running drift. Suddenly the engine smoked and stopped, we had to wait for an hour (with no anchor, currents and waves)before the captain repaired the whole with a rope, a nail, a piece of plastic or any expedient he found.
However, I can imagine how the dive on Monad schoals can be boring if you don't spot a biggie, it's as flat as the back of my hand, with as much corals and sea life.
August may not be the best diving period for Malaspacua as the place is not sheltered from winds and sea, lots of typhoons too.
However the island is heavenly, no cars, no girlie/party places just bikes and villages.
Exotic Island Resort is your best bet, very good dive centre, nice bungalows for 15USD per night.
Go there before it's too late !! Someday there'll be no more place in the world to spot threshers.