Wirral Coastguard teams were called out to 2 young females who had entered the water by Liverpool Victoria Rowing Club, West Float Dock, Birkenhead.
They became trapped after getting themselves stuck on the dock wall with a fence blocking the exit.
Merseyside Fire and Rescue Service opened the rowing club gate with a key they had on-board their vehicle
Two members of the Coastguard team then equipped themselves with water rescue life jackets, a floating line and a throw-bag and stood by in case the girls re entered the water.
Paramedics checked the girls over as they were suffering from the effects of cold and, as they had ingested some of the dock water.
The girls were transported to hospital for a more thorough check up.
Wirral Coastguard said: “Although the 2 females were safe, if suffering from the effects of cold, this could have had a very different and potentially fatal outcome.
“Docks are not areas to swim in, there can be underwater obstacles and cold water shock can affect the swimmer”.
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