Helensburgh RNLI has warned about the dangers people face when swimming in open water while under the influence of alcohol.

The warning was issued after a would-be swimmer was overheard on Sunday saying he was going to swim from Craigendoran pier to the wreck of the sugar boat in the middle of the Clyde estuary. The person appeared to have been drinking.

In a statement, Keith Shipman, Helensburgh RNLI’s volunteer press officer, said the lifeboat was launched just after 3pm and went to Craigendoran Pier.

He added: “The person was out of the water when the lifeboat reached the site, but the crew attending went ashore to check there were no medical issues and waited for the coastguard to arrive who then took over.

“At 3.58pm the lifeboat was stood down by UK Coastguard. It returned to station and reported ready for service again at 4pm.

“The RNLI warns about the dangers of entering open water whilst under the influence of alcohol.

“Apparently calm waters can hide strong tidal currents and the shock of cold water is increased by alcohol leading to sudden inability to cope with sea conditions.”