The cruise line did not have any excursions in Huatulco that seemed interesting so we chartered a boat for the day. The boat came with a driver, a guide/translator and snacks & drinks (including beer).
The guide met us on the dock and drove us to the boat. The van and the boat were both reasonably new, well maintained and very safe and the boat driver & guider were both very professional. We cruised along all the bays & beaches of Huatulco. We saw a fair bit of wildlife (including many sea turtles) and got some history about the area and bit of the locals spin on that region of Mexico.
It was a nice way to spend the day. If I pointed in a direction the boat went that way. I said I wanted to do some snorkeling and the guide asked what I wanted to see and we went there. Basically the boat and guide are yours. You do whatever you want to. When we had had enough the boat dropped us off on the dock near the ship.
There is a new shopping area right at the base of the dock to do the usual tourist shopping. A nice way to kill a little time before boarding the ship.