The Philippines has lots of sunken ships 
Best Snorkelling
I'm sure it does
But salt water isn't as kind as near freezing fresh water for preserving things
I never considered fresh water coral or artificial reefs (such that sunken ships create) 
For most people it is just too bloody COLD! And the fact that you have to have different equipment (long sleeve suit, INSULATED..etc) I spent enough on the warm water equipment, should I win the lottery I might consider investing...then again. I hate being cold.