Four teenagers were rescued by lifeboat crews after being cut off by the tide in the Mersey estuary in Wirral.
The group who had been out swimming were stranded on the rocks by Harrison Drive in New Brighton on Monday night.
A passer-by noticed the boys in difficulty and lifeboat crews helped get them to safety.
Mark Bland, from the RNLI New Brighton crew, said one of the group needed hospital treatment and the others suffered cuts and bruises.
"The crew happened to be on a training exercise so we were able to launch quickly," Mr Bland said.
"The group were cold and extremely scared when we arrived and had cuts to their legs, arms and feet where they had injured themselves climbing on to the rocky groyne.
"They were certainly in a very dangerous situation and have all learned a very valuable lesson." http://news.bbc.co.uk/1/hi/england/merseyside/8206811.stm