Cornwall Council has issued a warning, aimed particularly at young people, to highlight the dangers of tombstoning, the practice of jumping or diving from a height into water.

Captain Mark Killingback, harbour master for Truro and Penryn, said: “We have had complaints from the local coastguard volunteers at Portreath that they are regularly turning out to warn young people who climb around the railings and gain access to the finger pier even though the signs and information indicate there is no access to the pier.

"A few years ago in Portreath, a serious accident resulted in someone suffering from broken limbs and the individual had to be rescued by the emergency services. We don’t want to see a repeat of that kind of incident and people need to take responsibility for their actions and not jump into the unknown.”

He adds: “Colleagues at St Ives and Newquay have also reported dangerous activity there and we have had reports of young people seen jumping from Penryn road bridge into the harbour. Safety signs are being ignored.”

Harbour master at Bude, Paul Vincent, says: “We have also seen issues in Bude with people jumping from the lock and off the road bridge into the canal with the added danger that someone will land on a rowing boat as it emerges from under the bridge.”

The council said tombstoning can be dangerous because: Water depth alters with the tide and water may be shallower than it seems; submerged objects like rocks may not be visible and can cause serious injury; the shock of cold water may make it difficult to swim; strong currents can rapidly sweep people away.

Cornwall Council community safety manager Tamsin Lees said: "In some cases, young people are drinking alcohol in areas of Cornwall where tomb-stoning is popular. Mixing alcohol with water activities is particularly dangerous, and we would strongly advise young people to think about what it would be like if one of their friends were to be killed or seriously injured. We want young people to have fun, but please, avoid tomb-stoning and stay alive to enjoy next year.”

Cornwall Council cabinet member communities Geoff Brown added: “The message is clear if you do not know that the depth of the water is safe or you cannot see what is below the surface don’t jump. Think before you get involved.”

If you want to report a dangerous incident, please call 999 and ask for the coastguard.