The back kick is invaluable even for the non-photographer recreational diver. Without the back kick, the divemaster points to some animal, and the herd of divers swim over and jockey for position to look at it, each one kicking forward to leave the scene when he's done looking at it, and in the process kicking up silt and/or kicking in the faces of other divers trying to get into position for a look. Imagine if all of those divers could, one or two at a time, approach the animal, have a look, and then gently back away, letting the next diver take his position.