Police in Hartlepool are warning of the dangers of swimming in the marina after being called out more than 20 times this month.
Officers have been called 21 times since August 1 about youths swimming in the marina, and other calls about youngsters climbing onto boats, jumping into the water and setting off fire extinguishers.
Insp Mal Suggitt, from the local Neighbourhood Policing Team, said: “Large boats turn around in this area and people can’t easily be seen. Youths are putting themselves in danger of serious injury or worse and we would ask that parents remind their children of these dangers.
“We have recently identified a number of youths that had been swimming in the marina and we have visited them in their homes with their parents present to advise them of the dangers of their actions.
“We will continue to monitor the situation alongside staff at the lock office and we will put in place a dispersal notice which can enable us to disperse large groups of youths from the area.”