Our excursion was the Atlantis Adventures tour, which were guided walking tours to various aquariums and the "ruins." We walked through the lobby and casino too. Overall, we enjoyed this tour and was excited to see the sharks, rays, barracudas, and other sealife. Very similar to the Monterrey Bay Aquarium.
This is probably our favorite excusrsion. After going through 3-4 stops quickly (15 to 30 minutes each) where you can take photos and buy snacks/souvenirs, the tour ended at Maegen beach, which was absolutely beautiful. It had plenty of showers and facilities to rent body boards, kayaks, louge chairs, etc. Even the restaurant served some pretty good food - the stewed chicken was flavorful and perfectly cooked.
Most of this excursion was focused on Oriental Beach. Altough its very beautiful, there are less services here - only one shower and nothing to rent in terms of kayaks or body boards. They do offer free louge chairs, and at a $3 fee you can keep a large umbrella. The bar served stronger cocktails (rum punch) and more of it. The lunch (included with the excursion) was rather bland - the options were fish, chicken, and ribs.