Topic : What is the sail area of a MR?

Hi, question as stated really. i know that measured area ie two triangles is 10.2 sp.metres, but what is the real approximate area for a set typical modern sails?


Posted: 15/06/2007 14:52:01
By: James
Nominal area of Main & Jib with the modern rig is 9.96sqm.  Spinnaker is 10sqm.


Posted: 15/06/2007 16:24:52
By: Measurement Man
Only 9.96? That's less than a GP14.

Posted: 15/06/2007 23:20:20
By: James
Yes, but a merlin isn't shaped like a barge and doesn't have to drag 132kg of weight around ;). 

Also the Merlin rig is significantly higher which makes it more efficiant, and most - if not all - of the extra area in the GP is in the genoa.

Merlins use a sliding scale to determine the sail area as GGGG will tell you. You can have a short luff on the main but more area or a higher luff and less area. As with most of these things it's a compromise and we have landed right in the middle with a 5720 luff allowing 9.96 of measured area. Those sailing on the river tend to use the highest possible luff length to get clear(er!) of the trees, and i seem to remember a brief flirtation with a shorter main on sea boats when the carbon rigs first came in but I may be dreaming.

Posted: 16/06/2007 08:47:52
By: Chris M
Ok that makes sense, but you say "measured" areais 9.96 sp.metres. Is that not less than actual area?

Posted: 16/06/2007 10:54:05
By: James
It must be, but you're probably only talking about 1.5sqm as a rough guess. The 1/2 and 3/4 height maximums restrict the unmeasured area on the main.

Posted: 16/06/2007 12:44:08
By: Chris M
James, it may be less than a GP, given that the merlin has a small but very efficient jib, compared to the wacking great overlapping genoa sported by the GP.

You can see the lack of correlation between sail area and speed when you look at International Canoes, sailboards etc etc.


Posted: 18/06/2007 09:25:31
By: Measurement Man
I have enough to contend with without more sail area!

Posted: 18/06/2007 11:05:03
By: john
Sorry to ask a semi related question...  

I have a Smokers Satisfaction that has the main running in the boom all along the foot. Which is similar to the previous boats and yachts I have sailed.

I see from the photos the modern rigs are loose along the foot and I assume the cunningham and outhaul flatten the sail for beating? (as with my set-up) If I was to get new/second hand sails would a loose foot type sail work on my current rig or am I looking at a new boom?

Posted: 21/06/2007 10:01:49
By: Will 3200

I've just brought an NSM2, and asked Batt's a similar question:-
Basically, loose footed vs non isn't a real problem - the loose footed should be ok on an Ali boom (you can get a greater variation of curvature.
A modern sail will be cut with a little more luff round (carbon mast) than for an old Ali mast, but the differences may not be significant for my purposes (Club racing - not National Championships!).
The real problem I noticed (having scrapped a Smokers) is that the luff length is different on the more modern rigs. Our Smokers had a longer luff (5900) than the NSM2, this leads to a different foot length (2280 shorter than the NSM2 of 2500) and also a different permitted jib area.

You'll need to check the measurement certificate for the luff/foot dimensions and the jib area.

(Small advert - I've a Mainsail/jib from our old Smokers:
5900 luff 2280 foot (area of 6.73 on certificate) £30
Jib (3.12) £15
The mainsail was re-conditioned a couple of years ago and hasn't seen much use since. Drop me an email if you're interested)

Happy measuring,


Posted: 21/06/2007 11:15:11
By: Colin
Top tips, Thanks.

I seems I need to measure the mast and sails... I have not got round to getting a cert for the RYA yet as the boat is only just ready to sail, (families and houses...)

There are measurements written on the boom but I have no idea if they are correct!

As with yourself I doubt the performance difference is of value to me, even if I did notice, but it may expand the options for second hand sails...

Thanks again, I will let you know about the sails.

Posted: 21/06/2007 12:13:59
By: Will 3200

You should have the old certificate (?) The fgures on the boom should be the same as the certificate - if not, you'll need something remeasured.
I'm in the process of stripping, minor repairs, re-varnishing, re-painting. Then I'm going to have the hull re-weighed (20 years' ago it needed 1Kg of correctors). After than, I'll have the certificate transferred - that means only 1 payment! Re-measure first.

Do read the tuning tips as well (see Library)


Posted: 21/06/2007 12:20:08
By: Colin

Thanks, no cert, 3200 was acquired from a friend who was storing it in a car repair garage and had not got round to fixing her up.

The mast tip to gooseneck is 5900 and therefore the luff? The boom has the foot as 2370 and this is also written on the main, dated 1994! The jib is signed as 2.79m^2
I guess I stick to this style unless I want to re rig...

Is the weighing easy to do, or a major undertaking? I saw the pic in the building section, does it have to be at a builders?

And this may all be academic cos here in South-east Wales we are not exactly overwhelmed by numbers, and the time to race will be hard for me to justify to the better half... Although she might just like it...

Posted: 21/06/2007 17:06:16
By: Will 3200
Dear Will,

The Certificate (and actual mast band to gooseneck) for 2981 was 5900 (mm) and the foot 2280 (mm). The recorded jib size is 3.12 square metres.
Compare that with the NSM2 - luff 5720, foot 2500 - jib of 2.81 square metres.

The re-weighing is easy - if you have a Measurer handy! I've arrange that when I'm finished re-painting etc I'll take the boat to our measurer and he'll weigh it in his garage - I'm guessing about 15-20 minutes for the work (including the paperwork)
Previously (different class) I've had a measurer come and re-weigh (also re-measure - I changed deck layout).
The boat should be dry "to the measurer's satisfaction".

It's quite possible to buy sails to the Smokers design - you just have to talk to your sailmaker.


Posted: 21/06/2007 19:10:41
By: Colin
Thanks again Colin, I will see if she floats and then decide...

Posted: 21/06/2007 21:25:23
By: Will 3200
I do not know when the RYA went to a digital data base but it is just possible that they have 3200's measurements on file. Try asking Sebastian Edmonds (Bas) on 0845 345 0383. He was very helpful when I called round at RYA House to sort out a mistake on my certificate.
Happy restoring.

Posted: 22/06/2007 00:19:04
By: Peter 2789
I don't suppose anyone minds if you dont reweigh a boat of that age!

Posted: 22/06/2007 09:02:12
By: Mags
Mags wrote:-
"I don't suppose anyone minds if you dont reweigh a boat of that age!"

The difficulty is that the certificate states "Correctors - 1 1kg" (or something like that - I don't carry the certificate with me at all times ;-)).
The boat doesn't actually have the correctors fitted (now). If I ever get to an event where the certificate is checked against the boat (like Salcombe or the Nationals?), I'll have wasted more that the cost of the process.
As I need to change the certificate with the RYA, and the boat's sitting in the garage for mionor repais/re-varnishing/repainting now is as good a time as any.

Personally, I'd love the idea of a statment that "boats older than 20 years may remove correctors without re-measurement", but I just can't see that happening!

All the best.


Posted: 22/06/2007 10:03:59
By: Colin
Boats are never weighed at Salcombe but they are at the champs.  If I go this year (still chewing it over and looking at crew availability)  I will be taking some lead as I know there is some to put back in to Heaven Sent after the refit.  It makes virtually no difference at my end of the fleet if you have 2-3 Kg of correctors or not, but the perception of fairness is the issue and my own feeling is that enshrining this in the rules will lead to an unseemly scramble to find older boats with correctors in that can be ditched and repeated arguments over the fairness of same.

Posted: 22/06/2007 11:18:46
By: Andrew M
If someone bought 32xx to the champs, would anyone bother to weigh it, or even scruntineer it in any other way?

Posted: 22/06/2007 11:36:26
By: Mags
Yes they would Mags!  In 2000 Elusive was 17 years old (I think) and duly weighed and black bands checked in exactly the same way as the winning Time Zulu. (99kg with 2 corrector weights)  It's in the NOR & there's no opt out.

Do you want a go at the champs if you can persuade wife and twins of the attractions of North Wales? I'm still at chewing it over stage but getting more positive.

Posted: 22/06/2007 13:35:11
By: Andrew M
I am surprised, but its nice to see old boats are not made a mockery of! Shame on me for never doing the champs....but family duty calls (good job too, otherwise you'd all see how terribly unfit I am - 6 days on the sea? cripes!).

No chance of interesting the wife in North Wales, unless I can persuade it's made of Babybels, and there is a new Disneyland opening there...

Posted: 22/06/2007 14:20:12
By: Mags
Go for it Andrew!  See the write up in the magazine.  You'll love it!

Posted: 22/06/2007 17:56:41
By: Mike Anslow
as helm of 3379 at the Nationals, I insist on the boat being weighed!  Otherwise, I will feel that I am cheating when I beat all those new boats.
Come on old boats, be there!

Andrew M, come along and play.

Posted: 24/06/2007 11:57:54
At the Nationals at Poole in 1990 ? Roly-Poly 2156 was duly weighed.
She came in at 5 KG over minimum weight.
I happened to remark ( jokingly ! ) that I could now take the brick out of the bow tank.............Ever seen a measurer with his head stuck through a 100mm diameter hole ?????

He wasn't amused !!

No sense of humour ...some people.

The oldest boat there and never last in any race.....even beat Dick Batt in one race !!

Posted: 24/06/2007 15:19:24
By: Nigel


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