PC Phil McAllister says the dramatic incident, which took place on a foggy night in December last year, is one he will remember for the rest of his career.
The policeman was called out to an incident in Pinchbeck on December 9 after a man’s car had slid on ice and entered a water-filled dyke.
The driver was trapped in the car and bleeding but had managed to call 999 and tell the operator that he was in a lot of pain and that his car was filling with water.
PC McAllister, who was working alone, arrived first on scene. He spotted the car through the pitch black, foggy night and entered the dyke, not knowing how deep the icy water was.
A police spokesman said: “The conditions were treacherous and without a thought for his own safety PC McAllister entered the water to save the man.
“If PC McAllister had waited for specialist units to arrive, the outcome could have been very different.”
His quick thinking and heroic actions in risking his own life to help another, have now been recognised with a nomination at the national Police Bravery Awards.
Speaking to the Standard, PC McAllister explained what happened: “I located the vehicle upside down partially submerged in the icy water, with it continuing to fill with up water I descended the bank and jumped into the water.
“I was unable to open the door due to the way it was submerging in the water.
I managed to smash the rear window which was the highest part above the water due to the lower driver area being submerged in water.
“I then climbed into the rear cabin area and made my way to the driver and kept his head above the water line until I managed to free him from his seatbelt - which had locked tight due to being upside down while water was still coming in.
“I then managed to get him out the rear of the vehicle where he was pulled up the bank by the fire service who had just arrived.”
With the water being freezing cold, the paramedics who arrived to treat the driver, also attended to PC McAllister, giving him a foil blanket and treating some cuts to his hand.
Speaking about the award nomination, he added: “Its a privilege to be nominated for a national bravery award, I believe anyone would have done the same in that situation.
“I joined the Police to help those at there time of need and to protect the community I work and I will remember this incident for the rest of my career.”
Helen Stamp, Deputy Chair of Lincolnshire Police Federation, said: “The courage and professionalism shown by PC McAllister went above and beyond the normal call of duty.
“He showed exceptional bravery, and thoroughly deserves to be nominated for this award.
“Thank you PC McAllister for your dedication to helping to keep the public safe.”
Kerry McMahon-White, Head of Partnerships at Police Mutual, said of the awards: “Police Mutual is very proud to again be supporting the Police Bravery Awards. To each nominee, your achievements are extraordinary. We are humbled by your outstanding demonstrations of courage and commitment to protecting public safety in the most difficult of circumstances.
“At Police Mutual, my colleagues and I are deeply honoured to be able to show our appreciation for your bravery.”