ISC Rating

[robbieg]

Just received my ISC rating for the RTI race. Rather suprised to see that my boat-a 1989 Dehler 34 is rated as faster than a number of boats of 36 & 38 ft including a Ben. First 37 of similar vintage ? Don't know whether to be flattered or cross!

Any one any ideas why the ratings should throw up such strange results? The only thing I can think is that I'll be using a spinny-the larger boats rated below me may not.

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[Andy_H]

My Bav 32 rated 0.966 in 2002, but this year rates 0.986.
Nothing has changed so I don't know why the rating should. I have emailed ISC but no answer yet.

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[zephyrsailor]

i got a strait 1.00. odd since i have an IRC of about 0.92. i'm in the same group as sunsails france 2 and france 3!

<hr width=100% size=1><A target="_blank" HREF=http://www.yachtcruises.co.uk>http://www.yachtcruises.co.uk</A>

 

[boatless]

It's all part of the game. If you win it was your helmsmanship, and if you lose - it was the handicap.

<hr width=100% size=1>my opinion is complete rubbish, probably.

 

[bedouin]

Just checked my rating - 0.894, Aeolus in an identical boat rates 0.864.

I did a quick comparison of 2003 ratings against 2004 for boats entered in both and see that there is a significant variation in the ratings, some up and some down. Still ISC is not a rating system for serious racers but just a rough way of comparing the performance of different sorts of boats.

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[ChrisE]

..and remember that the ISC rating includes allowances for whether you fly a spi or have a folding prop, thus identical hulls can have different ratings.

Still, given this year's weather a have feeling that it will be a RTI drift rather than race.



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[dralex]

What is your rating, because I'm racing my 1990 Dehler 34 for the first time this weekend- do you have a folding prop because I think that will make a fair bit of difference- it certainly seems to in terms of boat speed.

Alex

<hr width=100% size=1>Life's too short- do it now.

 

[bedouin]

I think the only difference between Aeolus and Bedouin is that he has a 2 blade folder, I have a 3 blade folder, and my declared Genoa is a little bigger - but that hardly seems enough to justify 5% difference in ratings.

If the weather's light it's going to be a disaster for the later starting smaller boats. They've only given us about 2-2.5 hours to get to the needles before the tide turns foul.

My plan is if I'm off Yarmouth at lunchtime we'll stop there

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[ChrisE]

Yes, these ratings are interesting, we find ourselves (LWL 29') at 0.949 with Firefly, Andrew Bray's flyer (LWL 40' ish) on something like 0.999. I'd reckon that as they are probably lighter as well, the handicap time will be eaten up by the time we get to the Needles! Still we're only doing this for fun, aren't we?

I like your light winds strategy. I take the view that as soon as we start going backwards, we get to the pub as soon as the engine will allow.

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[Neraida]

We were all set to do this year's race until we read that we can't have the outboard on the back of the boat unless we leave it down and drag it for the entire race or take it off, which is not much of an option as if we do need it, we'll probably need it there and then and not after it's been lugged from down below and put on the transom. Pity really.

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[GeorgeP]

1.033 for me. No spinnaker this year though.

Hope you have a good race.

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[Will_M]

We are in IRC group 1 for RTI, our rating is 1.013 which makes us one of the slowest boats in the group, so probarly a good thing as every one we go past we beat!!!

Only bugger is, is our start time!!!! No drinikies the night before for us..

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[Aeolus_IV]

Bedouin,

Yes .. had spotted this and spoken to the ISC about this - they had no real explanation for the variation. The only differences between the boats I could identify was all up weight and sail area. I have taken sailing weight for the boat off the web, which is probably a bit on the generous side - let me know what you're displacement is and get it modified which should get me a bit nearer to you handicap.

Having said this, there are other boats from my club entering and they have much harder handicaps (indeed they are in a different start). These are boats I would normally expect to beat over the water (without flying a spinaker) - it could be that they are just not very quick sailors, or this is a quirk of the handicap system...

Are you heading for the Yacht Haven again this year? I finally managed to book space in East Cowes from Thursday night.

Regards, Jeff.

<hr width=100% size=1><A target="_blank" HREF=http://users.swing.be/FDB/centurion/index2.html>Centurion 32 Web site</A>

 

[alahol2]

Having never taken my own boat into the RTI, what is involved in getting a rating? Do you have to get the boat officially measured?


<hr width=100% size=1>I really would rather be sailing...

 

[Aeolus_IV]

No - there no official measurments involved, simply fill in the form with the facts about your boat, length, beam, water line length, sail area, type of prop/outboard etc. Then, if you do rather well, they will come and measure the boat for you (as I understand it /forums/images/icons/smile.gif).

The trouble is that while the physical aspects of a boat tend to be well known (ie its size), the weight of the boat is much harder to determine - few people have an accurate idea of what their boat weighs - I don't. I could be as much as 500Kg out. The sail area can also present some problems, especially with older boats which could be on their 3rd set of sails you cannot necessarily take the brochure areas, but need to take the sails down and measure them.

This is all highlighted in the differences between Bedouin and Aeolus - both Centurion 32's. I know that the sail areas differ, primarily since I have no head sail larger than 100%, where as Bedouin has a head sail of maximum size - possibly as big as 150%. I am also aware that our main sails have been recorded as slighly different, though mine is slightly larger in this case. I don't think that there is much to be done about these differences. The sailing displacement weight on the other hand should be more or less the same for which I am happy to take Bedouins' figures, he has been here and done this before, and has a much more accurate idea of the correct figure.

Regards, Jeff.

<hr width=100% size=1><A target="_blank" HREF=http://users.swing.be/FDB/centurion/index2.html>Centurion 32 Web site</A>