Bumps is a 3km rowing competition where your objective is to hit (bump) the boat ahead of you (or reach the finish line) before the crew behind you bumps you. Seventeen boats in various divisions race one behind another, separated by 1.5 boat lengths (1.5 × 20m), taking off all at once with the sound of a cannon! Once two boats bump, they exit the race by pulling off the course to let the race continue, usually at the relief of the boat ahead of them and the grief of the boat behind them. If the race is close, the boat that missed their opportunity to bump can start chasing the boat that thought it was safe. If they get caught, this is called an overbump.
Starting positions for the 4 race event is determined by the historical standing from the previous year. Once a bump (or overbump) is made, the boats come out with their positions switched the next race.
The race is full of tradition and history. Here are the posts related to bumps: