Fisherman David McMurdo said the new alert system saved his life.
A Scottish fisherman whose boat sank has said he owes his life to a new satellite alert system.
The Guyona went down so quickly on Tuesday, the three crew had no time to deploy the life raft.
The RNLI-designed system which sends out a location signal when a fisherman enters the water alerted rescuers who found them 50 minutes later.
David McMurdo, from Annan, Dumfries and Galloway, said: "It saved our lives - no doubt about it."
The crew were forced to tread water until their boat had fully submerged, allowing the life raft to release.
The alert was picked up by the RNLI at 1800 BST and passed to search and rescue teams. An RNLI lifeboat found the crew at 1850 BST, five miles south west of Sark in the Channel Islands.
Mr McMurdo is convinced the device saved their lives.
"If it wasn't for that, nobody would have known where we were. It's a great system," he said.
The crew faced an anxious time as they waited for their life raft to come free from the sinking ship.
"I was worried we were going to die, but once we got to the life raft I knew we were 90% safe," he added.
The MOB Guardian units use satellite technology to give rescuers an up-to-date position for a stricken vessel. A lone fisherman who falls overboard can also use the device to shut down the boat's engines.
Eighty fishing boats around Scotland have fitted the devices, or have one on order.