Rescue teams are searching for a missing swimmer off the coast of Skegness in Lincolnshire.
HM Coastguard said a swimmer had been reported missing at about 15:30 GMT.
A spokesperson said one of its helicopters had been searching the area along with Skegness and Mablethorpe Coastguard and lifeboats from Skegness and Mablethorpe RNLI.
Skegness RNLI said it had launched the Shannon Class lifeboat at the request of the coastguard and the search was continuing.
They would continue to help until they were stood down by the coastguard, a spokesperson said.
Lincolnshire Police has been contacted for comment.
