We have been to the area several times and snorkeled at Half Moon Bay on a couple of occassions. So, we decided to stay there, this time with our two daughters (17,20). We usually look for functional, but economical and #8 fir the bill. It was very resonably priced, and modestedly furnished. Downsides were trouble with the satellite on the lower channels, and amount of hot water for showers. Nevertheless, the condo is strategically located in the center of the bay with beuatiful 3rd floor views, a small pool, and small sandy area with palapas to lay out. Although it was unusally windy, you can always grab a snorkel and head out to the calmest area of the bay to see coral, fish, even lobster, crab, squid, .... and turtles.
1. Aktun Chen - do the whole thing - cave tour, zipline, and cenote snorkeling. A bit pricy but well worth it.
2. Kal-ku lagoon - - easiest snorkeling ever, but stick to the left and go back to the south end. Lots of rock formations to swim through and fish to see.
3. Tulum ruins - worth it, but crowded. Get there early and go straight to the main entrance. Then, hire a guide who can get you in without waiting in line.
We go to the big supermart in Tulum for supplies, so we can serveral meals for oureselves. But, we do like La Buena Vida and went to Tulum to eat a La Zebra and Zamas (two of our favorites).