Sail measurement rules

[Dave Croft]

Hi, I'm a bit out of touch lately with class rules and was wondering if someone can summarise the new rules with regard to changes in sail measurement. If I turn up to a meeting or two this year am I going to find my old sails are smaller than everyone eles's???  Thanks, Dave

[John Meadowcroft]

Hi Dave

I compared my 2006 main to John Thornton's 2007 main when I measured it.  We have similar rig dimensions.

The rule has only changed for the main.

The cross height allowances have changed, essentially a redistribution of allowable area.

Top height + 50mm
Mid height + 30mm
Bottom height - 75mm

At the top and mid height John's sail was larger by approx 50mm + 30mm.  At the mid height it was only smaller by about 25mm as my sail was not built to the maximum dimension.

So yes he has more roach above the middle batten.  I am told this translates to approx 0.4% actual useable area increase as few sails were built to the previous maximum at the bottom height (certainly the case for Alverbank and P&B) as the batten could not properly support the load and the sails wore out too quickly.

They will only be smaller than everyone elses if they were either small to start with or everyone else has a 2007 main.  Unlikely!

Hope this makes sense.

John

[Dave Croft]

Thanks John, that's clear. We might see you somewhere this season, Cadets allowing!