Pursuit Race Start Calculation

[xstucker]

I am performing the Race Officer duties at my local dinghy club tomorrow for the first time, and have just noticed that the first race is a pursuit. Does anyone have a formula or at least a process for working out the start times from PNs? Any help would be gratefully received.

Thanks in advance. Simon

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[William_H]

Pursuit Race here we call them a Handicap Start but I am sure it's the same thing.
You have to decide what you think the elapsed time for the race will be. I imagine you will use an average boat for this assessment. Then use the PNs to calculate the PN corrected time for each boat The time correction is the minutes needed to bring each boat to the same corrected time. This correction time will dictate the start time rounded to the nearest minute. Here at East Fremantle we have a countdown clock with big numbers from 30 down to 0. With really fast boats you may ask them to start on a + number of minutes but this is only really in novelty races where 40 footers race 18 footers. Obviously if the race is excessively long or short from expected your handicap may be wrong and if wind comes in after the first boats start or dies before the last boats finish you don't get a fair race but that is the luck of the game and the race shouldn't be taken too seriously. I hope your sailors have a successful race. I enjoy them. regards will

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[martinb]

This is not something I have had to do, but I would have thought that the starting point would be to determine the duration of the race, for example 60 minutes and a base start time. Then if you multiply the inverse of the handicap by the duration you will get a corrected time ie. for a boat with a handicap of 0.880: 1/0.880 x 60 = 68 minutes therefore starting 8 minutes before the base start time, a boat with a handicap of 1.15 : 1/1.15 x 60 = 52 minutes therefore starting 8 minutes after the base start time.

As I said, I have not ever had to do this, but it seems logical to me!

Martin

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[ChrisJ]

If you take a look at: http://www.burghfieldsc.org.uk/wednesdays/pursuit_board.htm
you will see a table that we use at our club. Across the top are various race lengths (which have to be decided on before you start). Then down the side are the different boats. The numbers in the middle indicate when you start.

We have a gun every minute until the last class starts, with some large numbers that get displayed showing how far through the sequence we have got. The numbers change every minute, and you start when your number disappears (i.e. your start number appears, and you have 1 minute left).

The finish is typically within 2 minutes of the official time, when the leading boat reaches a buoy. Once the leaders have finished, the finishing boat then motors back down the fleet recording the finishers as he passes them.

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