Only three places in the world you can do this, two off Big Island, Hawai'i. Unreal experience; more like watching flying aliens on another planet. You'll never forget it. They loop the loop close enough to touch (don't!) and are angels of the sea. The launch is very fast, 40+ knots? You won't get sea sick while moving but stationary you might. Take a very warm body wrap in addition to a towel as you can get cold from not swimming, and on the return.