I had read that if there was one dive I should do in my lifetime it was this. Wow. I'd say it's a 50-75% chance to see the graceful mantas (some with the wingspan of 16 feet)! There's not much else to see in these waters near the airport. Why near the airport? The lights are so bright at night they attract the plankton and the rays. Once the sun sets, all the divers from the dive boats go 30 feet maximum to the bottom and hold onto the rocks. The current is incredibly strong and when the mantas fly overhead, even stronger. This is the one dive where the more divers there are, the better the dive is. Holding underwater lights, we are attracting the plankton the mantas feast upon. We had 3-4 mantas that night and they performed a wonderful ballet. They truly come so close to touch the top of your head... This was such an amazing experience.
My husband and I originally booked the Manta Ray Night Dive three weeks in advance through an outfit called Manta Ray Divers for $75. Very few outfits do night dives. Well, oddly after we signed away our lives, they ended up transferring us to Neptune Charlie's boat which is the best thing that could have happened. Mark is fun and knows the mantas well. He knows the ocean well and is a great divemaster for the inexperienced and the experienced diver alike.
At the end of the trip we even had the option of purchasing a tape of the experience. Some boats take snorkelers as well.