Take an evening snorkel with manta rays on this 2.5-hour, small-group adventure in Hawaii — the only place in the world to swim with mantas at night. Take to the west coast waters off the Big Island around sunset. After a safety briefing, gear up and use a flotation board to hang out with these gentle giants as they swim just beneath the surface of the ocean. The Travel Channel called it one of the top 10 things to do, ever. Snacks and beverages are included.