18 Facts About Stand-by diver

Disadvantages are the absolute limitation on Stand-by diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba.

The disadvantages restrict use of this mode of diving to applications where the Stand-by diver operates within a small area, which is common in commercial diving work.

Definitive equipment for surface-supplied diving is the breathing apparatus which is supplied with primary breathing gas from the surface via a hose, which is usually part of a Stand-by diver's umbilical connecting the surface supply systems with the Stand-by diver, sometimes directly, otherwise via a bell umbilical and bell panel.

The breathing of the Stand-by diver is audible to the surface team over the communications system, and this helps to monitor the condition of the Stand-by diver and is a valuable safety feature.

The Stand-by diver must move his body to face anything he wants to see.

Related searches

The front port can usually be opened for ventilation and communication when the Stand-by diver is on deck, by being screwed out or swung to the side on a hinge.

The difference in pressure between the surface and the Stand-by diver can be so great that if the air line is cut at or near the surface and there is no non-return valve, the Stand-by diver would be partly squeezed into the helmet by the external pressure, and injured or possibly killed.

The spring force is adjustable by the Stand-by diver to prevent the suit from deflating completely or over-inflating and the Stand-by diver being floated uncontrollably to the surface.

Some helmets have an extra manual valve known as a spit-cock, which can be used to vent excess air when the Stand-by diver is in a position where the main exhaust can not function correctly.

Full-face mask encloses both mouth and nose, which reduces the risk of the Stand-by diver losing the air supply compared to a half mask and demand valve.

However it is quite practicable for a trained Stand-by diver to replace and clear a full face mask under water without assistance, so this is more an inconvenience than a disaster unless the Stand-by diver is rendered unconscious at the same time.

The Stand-by diver's end has underwater connectors for the electrical cables, and the air hoses are usually connected to the helmet, band mask, or bailout block by JIC fittings.

Pneumofathometer is a device used to measure the depth of a Stand-by diver by displaying the back-pressure on a gas supply hose with an open end at the Stand-by diver, and a flow rate with negligible resistance in the hose.

Each Stand-by diver has an independent pneumofathometer, and if there is a bell, it will have an independent pneumofathometer.

Surface checks are done after the Stand-by diver enters the water, but before he is allowed to descend.

Standby Stand-by diver will be prepared in the same way as the working Stand-by diver, but will not enter the water until needed.

Rescue tether or rescue strop is a short length of rope or webbing with a clip at one or both ends, which the stand-by diver uses to clip the unresponsive diver to his harness to free up both hands during a recovery.

Bellman is a stand-by diver who tends the working diver's umbilical from a wet or closed bell, and is ready to go to the diver's assistance at all times.