Senior lifeguard Bosco McAuley and lifeguards Bruce and Shane Traill were patrolling Whiterocks Beach in Portrush around 2pm on Thursday when they spotted something in the water 150m from the shore.
The lifeguards, who couldn’t tell what was in the water using their binoculars, immediately launched their rescue water craft and made their way to the scene to investigate.
Weather conditions at the time were very good as around 200 people were enjoying the sunshine on the beach.
The lifeguards soon discovered that the object was an old sofa which had been dumped into the sea. On recovering the item out of the water and away from public harm, the lifeguards proceeded to put the sofa on one of their trucks and safely disposed of it.
"While on one hand it might appear quite funny that we launched and recovered an old sofa from the sea, it is important to point out that our lifeguards, who are highly skilled and trained, acted in good faith responding swiftly when they noticed something unusual in the water," said RNLI lifeguard supervisor Tim Doran.
"We would always encourage visitors to the beach to alert us or phone the coastguard should they notice anything suspicious. We would always rather investigate the incident to find it is a sofa and all is well than not know and then discover too late that someone is in difficulty."
Doran added: "Our lifeguards will deal with a variety of incidents over the summer period and while I hope this will be one of the fewer types of instances, it does highlight the vigilance they show to keep our beaches safe."