Leaving Waimea, we pedal along a ridge of the Kohala Mountains before beginning the 2,500-foot descent back to the dry Kohala Coast, where sun-baked black lava fields are a stark contrast to the lush tropical forests we leave behind. After settling in at the Mauna Kea Beach Hotel, our elegant home for the night, there is time to go for a swim and snorkel and relax on the beach.