Well-organized Azul Profundo specializes in boat trips (with snorkeling and wildlife-watching thrown in) and sportfishing for marlin, swordfish, sailfish, tuna or mahimahi. Its main base is at Hotel Cordelias overlooking Puerto Ángel, but you can also make bookings in the internet cafe in Zipolite from where they can arrange pickups.
Four-hour snorkeling boat trips (M$180 per person, or M$250 with Zipolite pickup) go looking for turtles, dolphins and, with luck (from December to April), whales and take in four bays. You'll stop at least once for snorkeling and get a chance to go ashore.
A fishing boat for four people, with two lines, costs M$600 per hour (minimum two hours). All guides speak at least a little English.
Kayaks are available for paddling around in Puerto Ángel's sheltered bay for M$50 per hour.