A man has died following a rapid ascent while diving off northern France.

The diver, believed to be a 50-year-old man from Brighton, came up fast from 48m deep and was unconscious when he surfaced.

The crew of the Brighton Marina-based catamaran Seabreeze 3 called the French coastguard after the accident on Saturday and tried to revive him.

Coastguards sent a doctor out to the boat but the man was pronounced dead at the scene and the Seabreeze returned to Brighton Marina on Saturday evening with his body.

He was one of seven divers on the expedition 20 miles from the port of Le Havre.

Yesterday coastguards said no diver should attempt a rapid ascent from such a depth.

The Seabreeze 3 is a charter boat which can be hired for diving, deep-sea or wreck angling and mini cruises and holds up to 12 passengers plus crew.

It caters for all divers, from novices to those with more experience, and also works with a diving school to provide training.

Skipper Terry Lee did not wish to comment but a fellow charter boat skipper said diving accidents were always a potential risk.

Tim Bennetto, from Peacehaven, is captain of the Spartacat which runs diving and fishing trips from the Marina's West Quay along with the Sea Breeze and four or five other charters.

He said: "It is a potentially dangerous environment. That's why you dive in buddy pairs and do a lot of training. Sometimes if things go wrong people aren't ever found or if they are found you don't know what happened.

"The incident rate is actually a lot lower than something like horse-riding - I think there are about 25 deaths a year in the UK."

Mr Bennetto has been taking charter boats out for 25 years and said he believed the Seabreeze charter had been going for about the same length of time.

He said the expedition out to Le Havre would probably have been made up of experienced divers making descents to wrecks.

The British Sub Aqua Club, the governing body of British diving, reported in January that there were 441 diving incidents between October 2004 and September 2005, the highest number ever recorded.

Of those 17 were fatal and 98 were related to ascents - a 23 per cent increase on 2004.

The club's report expressed concern about the rising number of incidents but said it was not clear if the increase was due to more incidents, more people diving or better reporting of accidents.

A police spokesman said the man would be formally identified today.