Also a fan of Mead's bay along with Blanchard's beach shack for a reasonable, tasty lunch.

Straw hat is about a 10 minute walk down the beach for another lunch option while Malliouhana Resort and Four Seasons are on the opposite ends for an very high end experience

Since you are arriving early, you may request a taxi tour of some of the island and other beaches before being dropped off at beach.
You may be able to arrange for driver to pick you up at a designated time.
Don't be surprised if they do not request any payment until they return you to exit terminal