Commercial Diving is a major component of life in the offshore industry, with divers performing much of the subsea work. To better understand how the dive team accomplishes what they do we need to understand the hierarchy of the dive team onboard a typical dive support vessel.
The Dive Team On the bottom rung of the dive team is the Tenders. Ranging from fresh out of dive school right up to Lead Tender, these hands perform all of the support work required by the diver to properly do his job. Their station is on the vessels working deck & they will perform tasks such as sending tools to the diver, running compressors or other deck machinery required by the job, or in slow times doing all the basic maintenance that is required at sea.
Tenders are trained in a number of disciplines at dive school such as:
- Underwater burning & welding
- Offshore safety & survival
- Decompression chamber operations
Tenders build dive time doing surface dives to gain experience in the water. Once a certain number of dives is reached & they are declared competent by the Diving Supervisor they will “Break Out” & become full fledged Surface Divers.
The Surface Diver is the next step up. Generally first in the water on surface dive jobs, they will also assist the Dive Supervisor as he runs the dives.
On saturation dive jobs the surface diver acts as a stand-by. If one of the sat divers needs to come out of the system for any reason, the surface diver will then take that divers place. Then the lead tender will fill the surface divers position & everyone moves up a step, at least temporarily.
Saturation Divers have the most dive experience & will spend their time inside the saturation system, working at depths up to 1000′.
The system can generally accommodate from 4 to 16 divers & they are lowered to working depth in pairs inside the Dive Bell. One Sat diver will be in the water while the other remains inside the bell, tending the divers umbilical (which provides air, power, etc) & ready to go out & assist if required.
Saturation divers are the heart of the dive vessel, with the entire crew of the vessel working to assist that one person in the water.
The Dive Supervisor is in charge of the dive & the only person in direct communication with the divers. An ex-diver, the supervisor knows exactly what role everyone on the dive side of things will play.
The supervisor also acts as the liaison between all of the departments, including the Bridge, ROV, Sat Techs, LST’s, Divers, Tenders, Survey & the Client Representatives. This ensures that the safety of the diver in the water is always maintained as top priority, as it should be.
Life Support Technicians (LST) & Dive Technicians.
LST’s & Dive Tech’s are the crew behind the scene’s on a dive, making sure that the support equipment is functioning properly.
LST’s are responsible for monitoring the Saturation System, which is the divers habitat. This involves monitoring & mixing the gas which they breathe; a mixture of helium & oxygen for saturation diving (more on that later); operating air locks; constantly monitoring the divers inside the system visually; & providing the divers their meals. That last is handled by the trainee LST, AKA the Betty.
Dive Tech’s maintain the various mechanical, hydraulic & electrical systems associated with the dive system. This includes:
- Gas reclaim system
- Divers umbilical & helmet
- Communication gear
With the entire vessel acting to support the diver in safely completing his underwater task they are often the focus of the operation, but it is important to remember the rest of the support team that makes the diver’s job possible.
For a look at the various types of diving that are possible, take a look at This Article over at DP News.