A part submerged marker buoy, thought to be a danger to shipping, sparked a search operation at sea on Saturday.
Walmer’s RNLI volunteer lifeboat crew joined Dover Coastguard after 11am on Saturday, after the crew aboard a yacht reported the find.
Due to the size of the object, between 6 and 7 metres long, it was thought that it could be a hazard to other vessels.
Victoria Brophy, RNLI press officer for Walmer Lifeboat Station, said: “Walmer lifeboat was launched and proceeded to the last known position of the object, given by the passing yacht.
“Once on scene the lifeboat crew performed several search patterns but were unable to locate it.
“After the extensive search Dover Coastguard made the decision to stand the lifeboat down and Walmer lifeboat returned to station.”
A HM Coastguard spokesman said they searched about nine miles east of Walmer.
• Any sea users who come across objects that might be a hazard to shipping should report it to Dover Coastguard on 01304 210008.