Manual Deployment

Typically 60m of main umbilical to get to working depth and 30m of smaller excursion umbilical giving a total length of 90m.

The main umbilical would consist of a 3/8” supply hose, 5/8” return hose and a communications cable. It is weighted so that it is just negatively buoyant so that it sinks as it is deployed from the boat. The excursion umbilical fitted to the diver’s end of the main umbilical is a ¼” supply hose, ½” return hose and communication cable. This is slightly buoyant so that it rises over the sea bed.

The combined umbilical would be laid out on the deck or hung from a bracket. A tender would feed out or haul in the umbilical as needed.

Winch

As above with up to 150m of winch deployed main umbilical. This would avoid the need for a dedicated tender but involve greater cost and modification of the dive boat.

Diving Bell

Uses the existing main bell umbilical to supply and return gas to the bell. A 30m excursion umbilical with ¼”supply and ½” return would supply the diver. If two divers a using a common supply and return from and to the surface, balancing regulators in the bell will allow the divers to work at different depths.