SurfaceSupplied

SurfaceSupplied is a term used in diving to describe a breathing gas supply that is delivered to a diver from the surface through a hose. This method of diving, also known as surface-supplied diving or hookah diving, contrasts with self-contained underwater breathing apparatus (SCUBA), where the diver carries their breathing gas supply.

In surface-supplied diving, the breathing gas, typically air or a specialized gas mixture, is provided from a compressor or a bank of cylinders located on a support vessel or the shore. The gas is then routed to the diver through a flexible umbilical hose. This hose also often carries communication lines and sometimes power for lighting or tools. The diver wears a helmet or mask that is connected to the umbilical.

Surface-supplied diving offers several advantages. Divers can remain underwater for extended periods as their gas supply is not limited by the capacity of on-board cylinders. The larger volume of gas available at the surface also allows for higher gas flows, which can be beneficial for demanding work or for reducing breathing resistance. Communication with the surface is usually more reliable. However, it requires a surface support team and is less mobile than SCUBA. This method is commonly employed in commercial diving, scientific research, and military operations.