Mid & East Antrim Council is urging vandals in the Newferry area to stop removing life-rings after a number of incidents in recent weeks.
Four life-rings from along the River Bann and nearby slipway, as well as a cabinet which houses life-rings, have been taken.
Council has reported this to the PSNI and replaced the safety devices.
Mayor of Mid and East Antrim, Lindsay Millar said: “This mindless vandalism must stop. These life-rings are there for a reason, to help save lives.
“Council has done what it can to replace these as soon as possible, but they shouldn’t have been taken in the first place.
“It’s a shame that the stupidity of a few have now impacted on all Mid and East Antrim residents as the cost of replacing this essential equipment will now ultimately be borne by the ratepayers.
“I would urge anyone who sees anything suspicious to report it to the PSNI immediately. This borough has over 62 miles of coastline so is fortunate to have such fantastic, beautiful waterways to enjoy, but safely, and acts like this could cost people their lives.”
The Council has recently conducted a full water safety study and is planning to raise awareness of safety around open water in the coming months.