New Brighton lifeboat was launched at 5.15pm and were assisted by Merseyside Marine Fire & Rescue, with crew members from Hoylake lifeboat also attending the rescue.
The lifeboat crew reached the area close to the casualties within a couple of minutes from launch and immediately waded out in chest deep water to the two people and a dog.
The trapped teenagers were described as feeling the cold due to the waters low temperatures.
Graham Sale, lifeboat operations manager at RNLI New Brighton, said “This was a good example of a multi-agency operation in response to what could have had a very serious outcome.
“We have had several incidents this year to people cut off by the tide while walking their dogs. Its imperative that people know the tide times and movements in this area as the tide sweeps in rapidly along the many channels quickly cutting people off from the shore”.
The teens and the dog were unharmed and were assessed by onshore medical teams.