Lifeguards had to rescue a man whose drunken antics put his life in danger.

A seafront patrol boat happened to catch sight of the man, who had jumped off Brighton Marina for a dare and couldn't get back over the high marina wall.

He was already suffering from hypothermia when he was spotted by the patrol boat, which radioed for help.

It was the first rescue of the first weekend in action for Brighton's lifeguards.

The team of 25 patrols 13km of coastline from Saltdean to Shoreham every day during the summer, keeping holiday-makers safe.

Seafront officer Richard Pearce, 54, said the man had demonstrated perfectly the risks people take in the name of a bit of fun.

Mr Pearce, who has worked as a patrol boat operator and seafront officer for more than 20 years, said: "He would have fallen unconscious very soon if he had been left there much longer.

"Jumping in might seem like a good idea when you've had a skinful of beer but it's just about the stupidest thing you can do.

"Alcohol dilates the blood vessels meaning you get cold extremely quickly.

"You swim out of your depth, you will get tired easily, get very cold and you will drown."

Just as foolhardy are the huge numbers of people who jump off the groins, the stone walls that extend from the beach into the water all along the seafront.

Mr Pearce said: "We get so many people jumping off them and we see a lot of very nasty spinal injuries."

Some of the most common dangers are the least obvious ones.

Many party-goers and students enjoy barbecues and bonfires late into the night after the clubs have shut. What most don't realise is that the stones underneath their fires stay red-hot for days and frequently cause nasty burns.

Mr Pearce said: "We scour the beach in the morning looking for hot patches but you often can't see where they are.

"We had a five-year-old who had all the skin taken off the bottom of his feet after he walked on one."

Floating on inflatables, which may seem a sensible way to swim, is another surprisingly dangerous pastime and parents should also be aware that waves can quickly sweep small children off their feet.

Mr Pearce said: "Kids can be happily jumping waves which seems harmless but when the tide is coming in the waves get bigger without you realising.

"The waves break against the banks of pebbles and can pull out people who are light on their feet."

Mark Schwarz, 30, is a new recruit to Brighton's lifeguard team. He demonstrated how to use the new fibreglass rescue boards, which have replaced the canoes the lifeguards previously used.

He said: "When you reach the casualty you can lie them at the front while you kneel behind and paddle back. They are a lot quicker than the canoes and they can carry people back to shore who are unconscious."

Last year the lifeguards gave major first aid 22 times, rescued 18 people from the sea and saved ten lives. They also gave safety advice and minor first aid to more than 700 other beach-goers.