You could do a day starting at Trellis Bay, poking around there (Aragorn's Studio, etc) then stop at Long Bay, Beef Island (no facilities but a big long beach with OK snorkeling at the left end). Drive on to Josiah's Bay (surfy, fun! and gorgeous). Have lunch at Miss Naomi's on the beach, or drive up the hill to the Tamarind Club and enjoy their bar/restaurant and big pool.