A walker became stuck in rising floodwater while walking in a river on Christmas Eve.

The coastguard searched for the lone walker in Cuckmere River at Seven Sisters County Park, Seaford, as darkness fell on December 24.

Teams from Newhaven and Birling Gap used the WhatThreeWords app to locate the person. Every square metre in the world has been assigned a unique three-word combination, which a person in distress can give to emergency services as a location tool.

“As the mist and darkness came in the walker became lost and found themselves in rising flood water,” said Newhaven Coastguard.

“The teams were quickly on scene and carried out a search and rescue operation.

“The WhatThreeWords app proved very helpful in locating this person. In a coastal emergency dial 999 and ask for the coastguard.”

READ MORE: Hastings: Dramatic clifftop rescue after hearing cries for help

In June, walkers on a Hastings clifftop heard shouts for help from a man stuck in dense shrubbery and used the WhatThreeWords app to provide the coastguard with their precise location.

Coastguard officers finally found the man in dense vegetation in the country park and helped remove him from the "slightly precarious position".

He was escorted back to the car park where he could go home.