If you want to get away from the beach for half a day, take a hike up the local 'mountain' towards the western end of the beach, past all the hotels and heading to the old town.
It's more of a large rock formation, with a paved road in good shape winding up. Walking it is reasonably easy, but avoid the midday heat. At the top you will be rewarded with views across the bay. There is also a restaurant and a drinks kiosk. The top gives you expansive views out to sea, and if you climb around the other side you will also see views of the town and surrounding area. The climb is a great way to exercise after gorging on seafood at the beach.
The Travelfish newsletter is sent out every Monday and is jammed full of free advice for travel in Southeast Asia. You can see past issues here.