Fishermen, boat crew and recreational sea users are being urged not to interfere with the yellow buoys which are in use along the coast during the summer months.
The buoys are used to separate Eastbourne swimmers from fast-moving watercraft such as speedboats and jet skis.
Last year, six buoys, chains, shackles and anchors were lost because fishermen were tying their boats to the buoys and moving their position.
Jet ski enthusiasts were also using them as slalom lanes for racing, and sailing clubs used them as anchor points for their boats.
The cost to repair last year’s damage was around £2,500 and already this year two buoys, chains, shackles and anchors have been punctured and tampered with, costing another £500.
A council spokesperson added, “It’s important that anyone using the sea respects the equipment which is placed there.
“The buoys are not there for mooring up to, but are a vital safety aid.”