Youngsters are putting themselves at risk by playing on a high ladder next to the Fleetwood and Knott End ferry terminal.
Ferry operators are warning children not to risk serious injury after two boys were caught on camera at the Fleetwood ferry end, at around 9.30pm on Thursday.
Ferry skipper Tony Cowell said: “These children and others need to be aware of the dangers of climbing around the water.
“The boys climbed a high ladder next to the ferry, and should they have fallen they would have been trapped between the ferry and the dock with no-one around to get them out.
“The waters also have some very strong currents that they could have easily been caught up in if they did enter the water.
“Parents must let their children know about the dangers and stop any further incidents happening.”
Mr Cowell added: “No damage was done but there is also the potential of the vessel itself being damaged.”