After a brief synopsis of the rules, and putting on your wet suit, you board the Hawaiian traditional canoe, which holds about 6 people and you are taken out a very short into the bay, just after sunset. The water is calm in the bay, and at the appointed hour, we slid into the water and gathered around a modified surf board, which has a large light in mounted the centre. We were arranged in a circle around the surf board face down, with a "noodle" to help our feet float, looking straight down, as the guide turned the light on. It only took 3-4 minutes for the first giant manta to appear along the bottom about 20' below us. For the next 30 - 40 minutes it was magical. Another manta soon joined in and they swam from the bottom straight up towards us, then did an inverted loop right below our noses over and over again. These fish are actually feeding on the microscopic plankton that are attracted by the light, so it's a win/win situation. These giant mantas pass within inches of your face, but never touch. It is quite amazing.
At the end, you re-board the canoe, warm up with a very timely hot-chocolate and within minutes you are back on the dock and it's over. A fabulous must-see experience in my book.