Instead of numbers to assign guests their tables, use names of seashells. Each type of shell represents a different table. Arrange seating cards and shells on aqua fabric to give the impression of water. On each table, display a card with the shell's name, or fill a bowl with those shells as a centerpiece.
Open Ceiling Cave on Na Pali Coast, Kauai, Hawaii, USA. This cave is a hollowed-out lava tube, and may have served as a place where ancient Hawaiians could rest in their canoes when traveling along the coast. Photo by threeifbysea (Instagram)