To the occasional visitor, the Bumps is certainly a spectacular event, but it’s not exactly clear what is going on. Every 45 minutes a new set of boats, of apparently varying ability, paddle downstream past the Plough, line up in First Post Reach, and then set off hell for leather one after the other. Some quickly catch up with another boat then stop (sometimes amid scenes of complete disorder) for others the chase goes on all the way up to the Pike & Eel, unable to make up the last agonising inches. A few seem to have a gentle paddle over the course in glorious isolation. The same process is repeated several times a day for four or five days, twice a year. All very entertaining to watch, but what exactly is happening? What order do crews start in, and why? What are the crews trying to do when they race? And who is the winner at the end of it all?

‘Bumping’ is an unusual form of racing which evolved on the Cam during the 1820s. It allows races to happen, involving crews from a large number of competing Colleges, on a short stretch of river most of which is too narrow or not straight enough to permit more conventional side-by-side knock-out regattas. As more College crews appeared on the rowing scene, the race had to be divided into more Divisions. Currently there are seven Lent and ten May divisions, each with 17 or 18 boats, with about 15% of the University participating.

The Bumps can hardly be described as a fair or objective set of races. Aside from the many disputes over obstructions, missed bumps and so on, the races depend on history for starting order, and luck to win coveted ‘oars’; thus the fastest crew may miss out and not be rewarded. Basically, the Bumps are a continuous form of racing year on year where the finishing order of the crews for one set of races forms the starting order for the next. Whilst originally the Mays starting order followed on from the Lents finish, the two events have been independent from each other since 1887 with the starting order based on the previous years finish positions.

If you look at the charts of racing progress over a decade or more (such as those printed at the end of the Bumps Programme) you can identify those Clubs which are fading, holding their own, or building consistently. Even the best Clubs have bad years, to the dismay of their current members, but the overall patterns are clear.

To understand what is happening, it is easiest to think about a single Division. On the first day of racing, the crews turn up at the start and are lined up in the Club’s finishing order of last year. They pull into the bank between Baits Bite Lock and the top of First Post Reach. The starting point of each crew is defined by a chain attached to the bank, which the cox must hold. These are spaced so that there is a gap of about 90 feet (one and a half boat lengths) of clear water between each crew. Before the Division starts racing, there are warning signals (cannons) with four and one minute to go. Crews are pushed off the bank with about 20 seconds to go, whilst still holding the chains. The chain is dropped on firing the starting cannon, and all crews start racing at the same moment. The object of Bumps racing is to catch up (and ‘bump’ into) the crew in front of you, without being caught from behind. If a bump is inevitable, due to the potentially dangerous situation created when a much faster crew is behind a slower one, coxes are instructed to acknowledge this by raising their hand before physical contact is made; this is far better than carrying on regardless and causing a major hold up, not to mention damage or injury. The two crews involved in any bump then stop racing and pull into the bank allowing the rest of the Division to carry on. The boat behind them still has to carry on to the finish. If it is lucky, it can catch up three places to hit the crew that was originally ahead of the bumping pair, in which case it can move up three (or even five or seven) places in a single day - these are called ‘overbumps’.

While the crews are striving on the river, the loyal bank parties attempt to negotiate the perils of the towpath, while encouraging the crews using a variety of whistle codes (and some very flexible definitions of distance measures!) to pass information about how far ahead the opponents are. Combine this with the noise produced by sometimes thousands of spectators, and you have a true feeling of the Bumps.

On the subsequent days the same procedure happens, except that any crews that succeeded in bumping or overbumping on the previous day swap starting places with their victims. The only complication to add to the story is to explain the fate of the first crew in a Division. Any crew finishing in the top spot (either by rowing over from first position, or by bumping up to it), gets the chance to race at the bottom of the next Division as a ‘sandwich boat’. Although the crew clearly has to race twice in one day, if they manage to catch the boat ahead they take it’s place, the bumped boat moving down to the lower Division for the next day.

So who ends up the winner out of all the chaos? Clearly no crew has the chance to prove that it’s the fastest as the quick crews bump and stop before they complete the course! The aim, for at least the top crews, is to finish ‘Head’ - the first boat in the first Division, but this chance is only realistically available for those crews that start in the top five places. The beauty of Bumps however is that it is possible for crews at every level to be ‘winners’, given a little luck. If a crew manages to get a bump every day (i.e. go up four places) then they are awarded their oars - a blade painted in their college colours and illuminated with their crews’ names and boats they bumped. Most colleges award blades to crews that go up four or more places regardless of how they got there (e.g. bumping twice, overbumping but rowing over on one day so going up five places) but others are stricter. On the final day, you will be able to identify those crews that have won their oars as the cox will be holding an impracticably large flag while attempting to steer their boat.

Now that the process is a bit clearer to you, all that remains is to sit back and watch it all unfold around you. Be sure to watch carefully though, as back in the bar apocryphal stories of bumping on the last stroke, overlapping all the way down the Long Reach and how your crew were denied by the crew 20 places ahead will become yet more hazy in the years to come...