The wall or dropoff is actually at the end of the shelf, the point at which the realy deep water begins. Sometimes it takes the form of a very steep sand slope, while elsewhere it is a steep wall fissured by caves and canyons where protruding pinnacles are very much in evidence. In certain locations, the wall is oblitereated behind a veritable waterfall of sand, originating in the sand plain above. This spectacular river of sand is called a sand chute. Whatever their specific make-up, walls and dropoffs are what diving in the Cayman are all about.
Most dives are similar in general outline.
Your guide will take you thrrough a different groove on the way back to the mooring rope, which you ascend to perform a safety stop. A regulator and extra tank are usually suspended below the boat, too. If there is a strong current, a float will be lowered for you to grasp should the current carry you off. Since your guide is intiately familiar with wind and water conditions, don't hesitate to ask questions before setting off on your dive. They resemble fingers stretching from dry land out to sea, that is from shallow to deep water and the dropoff.