A soldier drowned when his tank overturned in a canal after sliding down a bank in Iraq, an inquest heard.
Lance Corporal Karl Shearer died in an accident on 1 April
Lance Corporal Karl Roy Shearer, 24, from Windsor, Berkshire, of D Squadron, the Household Cavalry Regiment, died in the accident on 1 April 2003.
The tank's commander, Lieutenant Alexander Tweedie died later but the driver, Trooper Wayne White, survived.
At the Oxford inquest, Coroner Selena Lynch recorded a verdict of accidental death while on active service.
Ms Lynch said: "Neither of these men would have suffered any pain - they would have fallen unconscious very rapidly and I hope that is of some comfort to their families.
"We owe both of these men and their families, thanks and gratitude for their having given their lives in active service for the benefit of us all."
The inquest had earlier heard from Trooper White about how the accident happened.
He said he turned a corner to follow two tanks over a bridge in the reclaimed marshy area of south-eastern Iraq when the back end started to slip to the right.
Lt Tweedie shouted to pull to the left but it was too late and the tank slipped down the bank and turned on to its turret, trapping Lt Tweedie and L/Cpl Shearer inside.
"Initially I wasn't able to open my hatch because of the pressure of the water trying to get into the vehicle," Trooper White said.
"There was no light in there. I managed to push the hatch and pull myself out."
The inquest heard that another tank slipped on the bridge a few days earlier.
'Doing his job'
Major Edward Haward, D Squadron's second in command, said: "Vehicles were slipping off crossings all over this part of Iraq.
"They got bogged in ditches, turning round, slipping off - it was a daily occurrence."
Lance Corporal Shearer's wife, Suzie Shearer, 28, attended the inquest on Wednesday.
Speaking afterwards, she said: "Karl was out there doing his job and what he wanted to do. I don't think this accident could have been prevented.
"Myself and Lauren will always be very proud of him and will never ever forget him."