Professional divers are usually trained in diver rescue for the modes of diving they are certified in, as part of the work of a professional diver is as stand-by diver to the working diver. The level and quality of training and required skill for certification may vary depending on the jurisdiction and relevant code of practice. During professional diving operations there will usually be a competent diver on stand-by at the surface control point, or in the water with the working diver, or both. The surface stand-by diver should be ready for immediate deployment for a rescue if this is deemed necessary by the diving supervisor, who is responsible for the safety of the dive team and for managing a rescue. Appropriate equipment based on the operational hazards and risk should be available on site. The bellman is the in-water standby diver in wet and dry bell operations.