There's a warning from Coastguards after an 18-year-old boy jumped off Durdle Door rock yesterday.
Beach goers watched on as the teen scaled the rocks and leapt into the sea just after 3pm.
Portland Coastgurard received two 999 calls regarding the incident and say he's lucky to be alive.
Watch Manager Bruce Lack says: "This young man is incredibly lucky to have survived this leap. At Durdle Door there is only one area of deeper water and if you miss this by a foot, you will land in shallow water. We believe that he is safe and well on shore although we have been unable to speak to him.
"This incident is similar to one that happened at Durdle Door a couple of years ago where a young man jumped into the sea and went straight down to the sea bed.
"A series of fortunate coincidences ensued. A diver happened to be on scene and rescued him from the sea bed unconscious, members of the public dragged an inflatable toy out into the water and got him back to beach where a medic happened to be holidaying and was able to give first aid. Twenty minutes later he had been airlifted to hospital and we understand that he made a full recovery.
"Most young people are not so lucky though. Last year five young men lost their lives after leaping from cliffs and other structures, known as tombstoning. Thirteen young people also sustained serious injuries such as dislocations, head and back injuries and broken bones.
"Please don’t jump into the water from cliffs, piers, sea walls and other structures. The tides mean that what may have been deep water only a few hours previously could be just a shallow puddle a few hours later. You do not know what is lying beneath the surface of the water and it is very difficult to gauge exactly where you jump."