We usually go to Tanayana Beach. You can do it by cab or through the ship. I have found that the cab only saves you $5 or so, so unless you want to do something special just do the ship tour there. The beach is nice, there is a buffet on the beach - burgers, hot dogs,, grilled chicken, and this sounds crazy,, but the best almond iced tea you've ever had.
The have bars along the beach and cheap massafges under the palm trees.
Great way to wile away the day.