Portsmouth Yardstick – what is it?

Firstly you need to understand that different types of sailing boats go at different speeds in the same wind.

Why doesn’t everyone sail the fastest boat? That’s an easy one to answer, the really really fast boats are basically a very large sail connected to a pencil. I don’t want to sail a pencil, I’m too old and I want to be able to sit down.

So how can boats that are so different race against each other? Well they can. Each boat is allocated a Portsmouth Yardstick number. When racing, all boats start at the same time (so you get the excitement of the race start) and at the end of the race the Race Officer corrects each boat’s time using the Portsmouth Yardstick number. Boats also sail for most of the race in the same wind!

Times are adjusted using this formula:

Corrected Time (C) = Race Time in Secs*1000/ Boat’s PY number

That looks easy! Yes in principle it is. It is complicated by number of laps (often slower boats don’t complete the same number of laps as faster boats) and understanding what is written on the race sheet by cold fingers. If you’ve ever had to be a Race Officer you’ll know that at the end of the race you need to see down with a pen & paper (or a piece of software called Sailwave) and shut yourself in a small quiet room knowing that later on you’ll be able to congratulate yourself with a beer.

So if I can do the results myself why use Sail Results? I ended up collating results for my local club. It is time consuming and I often found it difficult to read the scrawl from the race sheet of the day (is that a 9 or a 0?) – really frustrating. I simply wanted  something that was easy to use by anybody and allowed us to get on with what we enjoy – racing boats!

Does Sail Results do everything Sailwave does? Nope, absolutely not. Sailwave is a great piece of software but it has a steep learning curve and you need to be sitting in front of a PC to use it. Sail Results (PY) allows recording and calculation of results on the water in a simple way that fits with the racing we run at our club. I hope it fits yours!

If you need some more details about PY numbers there is full article on the RYA site here http://www.rya.org.uk/racing/Pages/portsmouthyardstick.aspx

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