 Several items of equipment are used to assist in facilitating accurate adherence to the planned profile, by allowing the diver to more easily control depth and ascent rate, or to transfer this control to specialist personnel at the surface.A shot line is a rope between a float at the surface, and a sufficiently heavy weight holding the rope approximately vertical.The shot line float should be sufficiently buoyant to support the weight of all divers that are likely to be using it at the same time.