If you really want to make a day of it in picturesque Kailua, rent a kayak and paddle to the twin islands off the coast of Lanikai called the Mokuluas. The journey to the islands takes a leisurely hour of paddling. Bring a picnic lunch and enjoy it on the beach. Then explore the island's coast, where you can dive into the blue waters of Sharks Cove. On your way there or back, make a quick stop on Flat Island, just a ten-minute paddle from Kailua Beach.