@betty - Congrats on choosing PG, I hope you enjoy your stay there. From the airport, you can take a taxi/Grab to Batangas City port, should be ~2H if early morn & no traffic. Negotiate the fare first bcos it's a long ride. I think the first boat to PG leaves at 6 am.
In PG, try to visit White Beach bcos the sunsets are great and it's also fun to ppl-watch. If you fancy a Balut (boiled duck embryo), there are many vendors around. If you eat one, my opinion of you will be higher, despite your gay macbook. Be sure to take pics for evidence!
Since you've booked at the Dive Resort, you can also go to the their beach resort & use the pool/beach. If you're booked on a weekday, try to get a room on the 2/F (but 1/F for Brits) and overlooking the sea. Who knows, you may even get the room that I stayed in! The views were great and it was very peaceful to stay in the balcony and have a meal or drink.
Re: the boat ride back, the sea can get a bit choppy during afternoons. I don't know how your sea legs are, so if you don't like rough seas, try to get a morning boat out of PG.
As you get out of the boat, there will be touts offering taxis to Manila or elsewhere. If you feel proletariat and want to ride the bus, just walk out of the terminal and you'll see the bus station (use my thread for reference). A bus to Manila (with A/C) should cost ~200 php. Taxi costs 2 to 3k.
If you have time to while away in Manila, you can go to Rizal Park, Intramuros (the walled inner city) or Mall of Asia (MOA) and Manila Bay. There are many nice restos outside of MOA - very pleasant to have beer/coffee and spend time while waiting for your flight. Those areas aren't too far from the airport either.
You can leave your luggage at MOA (SM Dept Store or National Book Store) for free while you explore. They'll give you a bag tag just like in the supermarket - I've done that before. Just make sure you have no valuables in your luggage.
You can also leave your luggage for free at the Mall in Resorts World. There's a big mall and casino. RW is very near Terminal 3 Airport. BTW, if your flight is on a Fri night, make sure you leave for the airport early. The traffic during Fridays is horrible - I almost missed my flight one time.
BTW trivia for the Brits here: PI was under the Brits for a few months, but the UK "gave" PI back to Spain as part of the Treaty of Paris in 1763. There was another Treaty of Paris (between US and Spain) in 1898, which also concerned PI.
Cheers and happy vacay! Take lots of pics!