[Humber Coastguard]

If a diver requests to go on oxygen for safety reasons it implies that he/she believes that they have pushed the decompression boundaries and is concerned that they may suffer a hit if they don't breathe oxygen.

The dive boat skipper was quite right in wanting to give us, the Coastguard, a heads-up. Should the diver subsequently show symptoms then if we are prepared we can get the diver to the chamber quicker. Bear in mind that Rescue Helicopters are not sitting on the tarmac with their engines ticking over waiting for a diver to get a bend, they may be out on another job.

When the Coastguard is alerted to the fact that a diver has made a fast ascent, has missed a stop or is showing symptoms of DCI we put the Diver/Dive Marshal in direct contact with the Duty Diving Specialist at the Institute of Naval Medicine. They will then discuss the dive profile and symptoms, or absence of symptoms, and the doctor will decide whether the diver should be evacuated or not.

If there are no symptoms and the dive profile was reasonably safe (not a lot of missed decompression) then the doctor will probably just request that the diver is kept under observation by the other members of the dive party - and by the diver himself.

Don't think that a call to the Coastguard is a guaranteed helicopter ride. Your dive boat skipper is just playing safe, making sure that if you do develop symptoms then we know where the nearest SAR helicopter is, the crew know that they may be tasked and we know which chamber is available - we are prepared.

ALWAYS CALL THE COASTGUARD!

Just one more point. The fact that you have been breathing oxygen may delay the onset of symptoms and you could get a hit while driving home, it has happened. Breathing oxygen has also resulted in divers with no symptoms being flown to the chamber because the doctor was concerned that the oxygen could be masking symptoms.