The Cambridge crew in this film were played by members of the rowing squad from Imperial College, London, including several members of the British international squad.
The depiction of the race includes real footage of the Boat Race in 1997 - the problem being that the crews are the wrong way round. This can be seen during one of the cuts between actor crew and actual Boat Race footage.
Consecutive (in the final cut) shots of the race are inter-cut from takes made at very different states of the tide. The water level in the river goes up and down like a yo-yo between them.