I went to PG twice and both times I stayed at Small La Laguna beach. That's about a 10 minute walk from Sabang, and is quieter and more laid-back, but still not far from Sabang's various restaurants and bars. I did my diving with Action Divers. The first trip, I was quite impressed with them. The second time, they were less than perfect (they had a lot of customers so I ended up diving in a group with 5 other divers who went sprinting away down the reef before I could even change my camera settings. . . not the DM's fault, but not ideal). Action Divers can arrange cheap or mid-range accommodation for you at Small La Laguna beach, or you can do some research and arrange your own. I have heard good things about South Sea, as Centrals recommended, but they're in Sabang, which isn't quite as mellow as Small La Laguna beach.
If the Si-Kat doesn't match your schedule, you can arrange for a private transfer from Manila to Batangas, where you catch the ferry to Sabang beach in Puerto Galera. If the private transfer's too expensive for you, there are cheap public buses from Manila to Batangas. You need to arrive in Batangas by mid-afternoon to catch the last ferry to PG (I think it leaves around 4 pm). If you decide to stay somewhere along Small La Laguna beach, then when you get off the ferry in Sabang you can hire a porter or two to carry your scuba gear, suitcase, etc. for a reasonable price.
