Crews boarded a boat which was in danger of capsizing on the Cromarty Firth and used specialised equipment to pump gallons of water from the vessel.
A rapid response operation involving Invergordon lifeboat, and coordinated by Aberdeen coastguard, was mounted at 7am on Saturday when the dredger, WD Mersey, hit an underwater object.
The RNLI Trent Class lifeboat and her volunteer crew were deployed to prevent the boat, which has been working at Nigg Energy Park, from going down.
Two crew members went on board and used a salvage pump to displace water from the stricken vessel before she was escorted safely back to Nigg to allow the damage to be inspected, by 11am.
Local divers have since carried out a thorough assessment on the hole and it is understood that it can be repaired to allow the WD Mersay to return to its work, which is part of the ongoing renovation project at the energy park.
Michael MacDonald, spokesman for the RNLI crew at Invergordon, said: “An ingress of water was flowing into the boat, so time was of the essence to prevent her sinking or capsizing, as the water was coming in quicker all the time.
“Two crew members managed to stem the flow of water and we were then able to escort the vessel back to the harbour at Nigg Energy Park to await the divers’ arrival.
“It was an unknown object which caused the damage, there are may things under the water of the Cromarty Firth which would have been enough to puncture the boat.”
Nigg Energy Park, which is owned by the Global Energy group, is undergoing a £6.5million development, which will transform its quayside on the Cromarty Firth.
Plant equipment, including numerous cranes and diggers, have been operational at the site for many months, with the WD Mersey an integral part of the ongoing operation.