The water temperature in Coron Bay and around Busuanga Island ranges from 27 to 30 degrees C or 80 to 86 F depending whether the dive site is deeper or shallower and how long the water has been sitting warmed by the sun before the tidal current moves it away.
Starting sometime between September and November and on through to the first or second week in June the weather is sunny so you can warm up between dives as long as you take off your wet suit and dry off. You will have a surface interval of one to two hours between dives. Normal wet suits at dive centres in Coron are 3 mm / 1/8 inch, one-piece full suit. Wearing shorties is not recommended as, unless you are particularly careful, you are likely to cut yourself going in and out of the wrecks.
If you're prone to cold, or you are bald, or you normally dive with a hood, pack it with your dive gear and you will be more comfortable and/or will not burn your head.
Unlike reef diving, we recommend you bring dive gloves to protect your hands from stingers on the mooring ropes and from nicks and cuts on, and in, the wrecks.
It is a essential you bring a hat, a loose shirt, and sun-block for sunburn protection. Although the boats are covered you will spend some time in the sun. If you come out of Northern Europe, Scandinavia, or the UK in midwinter, the Philippine sun can burn you with little exposure. Make sure you cover up and spread on some sunscreen with a SPF of at least 30.