Makua Beach, also known as Tunnels Beach, located on the north coast of Kauai, is one of the best snorkeling spots on the island. It includes shallow areas protected by a coral quarry and reefs open onto the ocean, and you can explore a range of environments and varied underwater life: a whole medley of fish, green turtles and, if you’re lucky, an encounter with a Hawaiian monk seal, all of which pay regular visits to the site.