The beach at the port is not very impressive, but thoroughly enjoyed my beach visit to Majahual. You can take a taxi there, but I would suggest renting a golf cart and doing a little exploring on your own on your way to Majahual.
We ate at one of the "restaurants" at the beach at Majahual. It was a beer/food stand more or less. I don't remember it's name, it was recommended by our excursion guy. We did not eat at the Costa Maya port. Enjoy, Lil' Lori
There are a number of bars and restaurants at the pier, however, I found them to be overpriced and mediocre. For great food head into Majahual. I would recommend Tapas Bar, but they are presently closed for renovations. So, my alternate choice would be El Faro. This beachside palapa restaurant serves inexpensive, but excellent, fresh grilled shrimp. I also had friends that raved about the ceviche at La Guera.