Mr Lamb, 39, and Alan Merrigan, 30, were trapped in the Sierra as it sank in 10 feet of water at Seahouses. Two other passengers, Caroline Budge, 20, and Stephen Charlton, 39, were rescued by fishermen and taken to hospital suffering from shock.
Mr Charlton, of Bishop Auckland, Co Durham, said: 'The car turned over and went into the water. Everything just went black. It must have filled up with water in about five seconds. I managed to scramble out of the front passenger seat and the next thing I knew there were hands dragging me from the water.'
A Northumbria police spokeswoman said the four people in the car had been guests of a local pub licensee after normal hours and on leaving drove the short distance to the harbour.
Chief Inspector Noel Wanless said police did not know why the car, which was not travelling at an excessive speed, suddenly hit lobster pots and the quayside barrier.
Ridley Lamb, who was the stable jockey at the late Arthur Stephenson's yard in East Fleetham, had his greatest success when he won the 1987 Cheltenham Gold Cup on The Thinker.
Mr Lamb, from East Fleetham, rode more than 500 winners, coming a close second in the 1978 Grand National and winning the 1977 Scottish National.
After his retirement he became a trainer and achieved his first win in April 1990 at Hexham for Jack Riddell.
Obituaries, page 12
Racing, page 29