Oban RNLI was called to rescue a diver who had fallen unconscious while in water.
The casualty had been free diving with four friends off Maiden Island, at the northern entrance to Oban Bay, before he was discovered face down, unconscious and not breathing after surfacing from the water.
Oban Lifeboat Crew launched at 3pm after the Stornoway Coastguard called for assistance on Monday.
The crew were joined on board by two Scottish Ambulance Service paramedics.
When the lifeboat arrived on scene, the casualty was located on rocks to the north side of the island and was transferred to the lifeboat for treatment by paramedics during a fast transfer back to shore, before being taken to hospital.
Their current condition is unknown at this stage.
Oban Lifeboat Coxswain Ally Cerexhe said: “This was a multi-agency rescue, not just involving our colleagues from the Scottish Ambulance Service but also Coastguard teams on the shore and the Coastguard helicopter Rescue 199 from Prestwick.
“We’d particularly like to thank the crew of a local fishing boat who were helping on the scene when we arrived.”