The water is gorgeous there. This is a new port and the water is very "untouched". We looked into the water near the ship and saw all kinds of fish - the water was so clear.
Many people took a taxi for about $5/person to a gorgeous beach and raved about it. The beach (I don't remember the name) had bar service, etc.. I spoke to several separately and they all seemed to go to the same beach. There are several taxi drivers available after you walk the 5 minutes to the shopping area in Costa Maya. The taxi drivers are very eager to please - they offered to come back and pick these people up at a designated time.
The shopping is expensive there but cute - it is about 2x as expensive as Cozumel shopping.
Don't know about snorkeling. Not a snorkler.
If you don't go to the beach or the ruins you will probably be bored at this port. The shopping is nice to walk around but won't take more then 2 hours. There is a public pool available free of charge in the center of the shopping area. There is also some Mexican dances going on to entertain people.
Here are some pictures of the shopping area and the pool along with pictures from our Grand cruise:
We were there with Theresa on the Grand. Next time we go we will definitely go to the beach and swim. It was a quite warm there and the water would have felt wonderful. I don't think I have ever seen such clear and beautiful water as what we saw there. My husband, daughter and I love to snorkle and wish we had chosen that to do. Like Theresa said, when the four of us were walking back to the ship (had sent Bunny and Erin on ahead) we were amazed as to how many tropical fish we could see off the pier.
Now the shopping I wouldn't bother with either. I know they are trying to get it started, but everything was very expensive compared to Cozumel and from when we were in Cabo a year ago. In this port it was hard for them to take NO for an answer which made me feel guilty at times, but just didn't want to spend that much.
Go to the beach and you will totally enjoy this port. The ruins trips are also supposed to be quite interesting if you want to go that route also. Theresa and I looked at the swimming place in the shopping area, but decided it looked too hot to even think about.