THRILLSEEKERS are being warned they risk serious injury or even death if they hurl themselves off the Harbour Arm this summer.
More than 14 people have died nationally in the last four years while tombstoning - a high-risk craze which sees people jumping off cliff faces or rocks into the sea.
And here in Hastings local youngsters and visiting tourists have taken to leaping from the Harbour Arm on The Stade into the often shallow and rocky water underneath.
There have not yet been any serious injuries reported, but Sussex Police is keen to stress the very real dangers associated with the activity.
Inspector Gareth Davies, speaking on behalf of Sussex Police, said: “Tombstoning is an extremely dangerous practice and we cannot advise strongly enough against it.
“It is very hard to judge the depth of water due to swell and sea conditions and to see any objects lurking below the surface. Serious injuries, sometimes resulting in death, are often sustained from hitting the seabed or an underwater obstruction.
“It’s not worth ruining your life for a dare or a quick thrill.”
Earlier this month a day-tripper was left nursing serious injuries after tombstoning off Brighton Pier into just three foot of water.
And police say this accident illustrates perfectly why locals should give the activity a wide berth, quite simply because it is imposssible to tell what you are leaping into.
A spokesman for the Maritime and Coastguard Agency agreed and said the danger of tombstoning far outweighs the short-term thrill.
But, according to the expert, it is not just shallow water people should look out for.
The spokesman told the Observer: “Jumping into deceptively shallow water is not the only danger posed by tombstoning.
“The shock of cold water can make it difficult to swim and strong currents can rapidly sweep people away.”
And they warned: “Think before you jump. Don’t let alcohol, drugs or peer pressure affect your judgement.
“Even if you are jumping safely, children may be watching and copy your actions.
“Don’t jump into the unknown.”