Hi

I am trying to find the correct portsmouth yardstick for a formula 16 (two up)at the moment.

I have 652,673,689,698,730 numbers any ideal which is most correct today.

The boat is to be race in switzerland.

Bye

The US Sailing Portsmouth numbers are here, but not sure if this is the rating system used in Switzerland.

65.2 is the basic number for F16 2-up. The other numbers in the table can be used to account for different wind speeds.

Hi John

How are you? Hope everything is going well for you and you are blasting around with stealth!
Are you planning to sail, at the lac de joux in august?

In the french part of switzerland, when you sail against different catamarans, they use the the ISAF handicap system.

In the german part, it is partly the ISAF handicap system or the Texelrating system.

I guess there is allready a handicap for stealth in both systems.

If you are looking for a handicap between all kind of boats (multis and monos mixed).
I don't know how they do it at lake of geneva, but here at the lake of constance (bodensee) they take the texel rating and use a factor of 0.76 to compare monohulls and multihulls. But this can be different from lake to lake ;-)

Here at the bodensee, there is the yardstick commision and you have to ask them for a rating. You just need to send them the spec's of your stealth and you get a rating.

Good luck!

Andi

689 is not too far out. Or look at the SCHRS website <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

US Portsmout Yardstick 66.9
SCHR 1.075
SCHR( RYA Portsmorth

Hit the wrong key last time.
Rating for two up F16.
US Portsmouth Yardstick 66.9
SCHR (ISAF) 1.075
Texel rating 102
RYA Portsmouth Texel convertion 77.52 (102*0.760)
RYA Portsmouth SCHR convertion 737.45 (1.075*686)
RYA Portsmouth LOSSC 731

Time to get sailing now.

John, where do you get a SCHRS of 1.075 for a 2 up F16? The rating for a 2 up F16 is 1.020 !

perhaps he has entered the max allowed sail area for F16 @15m2 plus an extra bit for the section of mast F16 don't measure but schrs do , see in ratings mainsail area is 14.85 which is probably what f16s use other than max allowed for some reason , just a thought

whilst on the subject of handicaps its goes against my grain but it would seem the PY systems have one advantage and plenty of disadvantages over SCHRS , in that py would recognise that f16 solo and two up travel at the same speed , this is widely accepted and proved by the fact that f16s allow solo and two up to race on equal footing , py should on returns hcap both the same (won't happen in uk as most folks race on SCHRS - which otherwise is much better and there will never be enough returns to calculate )
SCHRS as its a measurement rule can't correct this anomily ,although Scooby et al is working on it slowly , the righting moment element has helped albeit very small .
This anomily affects all solo sailors in schrs and f16 is a good case as it highlights the penalty on solo sailors , who are allready handicapped by having only two hands !

Extra area would make it faster,. not slower !






The thing is, the info we(the SCHRS group) have does not bear this out. The results of the GC in Zandvoort will be very interesting and will help us.

In our opinion a well sailed F16 one up (and assuming wiring down wind as this is the way to sail single handed) appears to be quicker around the course up to around top F4, then the 2 up boats do get a little faster; I would suggest more races are sailed in light to moderate winds and are stronger winds (F5 upwards). Thus we currently believe the SCHRS numbers are about right for the F16. More info is needed by us !

It would have been very interesting to see how the Mumbles results would have been different if Paul had been sailing 2 up on Friday when it was windy (and so he would have done less swimming and we would be able to compare like with like), if Mark had not swam on Friday and if I had not broken my boat (and rememberd to count)

This is the first year that the Stealth F16's have had sails that have been specifically cut for sailing single handed (myself, Mark P and David Tugwell), these are considered faster by a fair bit.


I'd like to ask the Race team for a copy of the results (and times if taken) to allow the SCHRS group to review them. Also a wind map for the day would also help.

so eyes talking a load of butt again sorry , hadn't heard you solo guys had stepped up a gear relatively

hmm apolgies too my bad, all these zeros after the point gettin confusing, my addled brain had mentally added one !

I have raced against Paul and Paul and Anne more than most others and we are both of a similar speed when racing solo. The winner is often the one who makes the least mistakes. However, when Paul is two up I feel the single handed boat is practically the same speed upwind but faster downwind up to and including force three. I'm not talking about super light winds either as we haven't competed against each other yet in those conditions. When the wind increases above force 4 Paul and Anne's upwind speed is quite a bit quicker than me and having the extra pair of hands for the spi handling also helps them increase their lead. So in summary it's horses for courses, light, medium winds solo seems the quicker anything around or above force 4 two up is quicker. Mind you it shouldn't take a mastermind to work that out.

Hi

I took the rating for the Stealth on the SCHRS web site, thinking it would be the same as a F16. My mistake.

Bye