This sightseeing boat is cruising along the Wailuā River in Kaua’i. The river is formed in the Wai’ale’ale Mountain which has an elevation of over 5,000 feet. From there it flows for twenty miles from the center of the island until it empties into the Pacific Ocean near the town of Wailuā on the east coast. Another popular way to experience the longest navigable river in Hawaii is by kayak or stand-up paddleboard.