The Coastguard was called out to a north-east harbour following reports of people tombstoning.
Officers attended Stonehaven Harbour yesterday for the fifth time in the last few weeks to warn people about the dangers of taking part in the stunt.
The hot weather is attracting high numbers of visitors to the coast, with some tombstoning from the harbour wall.
Senior Coastal Operations Officer Calum Christie said: “We always urge people to have fun but stay safe when out enjoying our beautiful beaches and coastlines.
“Jumping from piers, cliffs, rocks or other structures into the sea can be very dangerous.
“The depth of the water can dramatically change with the tide, and what was a deep pool at lunchtime might be a shallow puddle by teatime.
“You don’t know what hazards may be lurking under the surface until you are hurt or worse. The shock of cold water may make it difficult to swim to safety and strong currents can quickly sweep people away.
“If you do want to jump from height into the sea we would advise people join a coasteering group with a professional and reputable adventure centre.”