Depth:  30 – 40ft Location:  Dead Chest Island At this site the volcanic rock has been carved by centuries of wave and tidal action in to long galleries, caves and tunnels, the sides of which are festooned in brightly colored sponges – hence the name.  Turtles can be seen and small Caribbean reef sharks often hunt in the gullies.  In the third canyon a small circular cavern faces you, covered in orange and yellow sponges, while branching to the right is a huge natural arch which superb for photography.  Surge can be experienced on the surface.