WHat size jib (s) should I buy?

B

BlueSkyNick

Well-Known Member
Joined
29 Apr 2003
Messages
11,766
Location
Near a marina, sailing club and pub
Visit site
Have always been keen on having a smaller jib on a second inner forestay, but never got a round tuit.

The main reason is that a semi furled genoa doesn't do it for me, pointing to windward. Much less than 40degs to AWA and we struggle. I would like to be able to hoist a smaller jib and set it properly, and hopefully find it easier to handle.

I already have a suitable strong point on the foredeck, for a temporary forestay. Previous owner suggested using the spare (wire) halyard, winched up tight, but even just putting up the storm jib in fairly light conditions it was saggy. Hence the sail is useless which is why it is still as good as new.

Question is, what size jib to buy to fill the gap between genoa and storm jib. No1 seems a bit big, will a No.3 be too small? How do I know what actual size these sails would be?

Just copied this numbers off the Moody Boat Archive site.

I 16.49m 54'0"
J 5.08m 16'8"
P 14.17m 46'6"
E 4.77m 15'8"
SAIL AREAS
Roller Genoa 58.59m² 630 sq ft
In-Mast Furling Genoa 33.85m² 364 sq ft

Its a masthead rig, BTW.
 
Nick, If you add a foam luff to your existing genoa you will get a far better sail set and might be cheaper. The chaps at Hood are very helpful
 
Good #4 size is 85% of I and 85% of J. A longish luff length will help your pointing. Have the clew cut highish so it won't scoop water when reaching. I've used this formula in the past and intend to again. Chat to your sailmaker and get him to measure up for best results.
 
Agree with you re limited reefing ability of a roller genny for windward work. Have been thinking the same for my boat but as already have a baby stay the (small) foredeck could get crowded!

Even thinking of doing away with baby stay and rerigging as a cutter but will need professional advice before progressing this.
 
Recently been thro' similar process. Assume your IJ are for forestay triangle. My sailmaker (hanked-on cruising jib) advised maximising forestay length (I) on inner stay. Inner J 100% so resulted in a foil type jib - awaiting delivery so can't give performance details. A good Sailmaker should give you sound advice to meet YOUR needs/vessel.
 
Thanks for this and the other responses. We are not short of sailmakers nearby - had an excellent experience on the previous boat, through Kemps, and now getting to know Sanders pretty well for a totally different reason.

I guess I am really trying to find out the most useful size, given that I really only want to buy one sail, based on the experience of others on here.

I thought IJ are standard measurements for the forward triangle or can they be something else ??

A bit concerned about Michael's suggestion to keep the clew out of the water - Moody boats are not renowned for being sailed that far over - the more upright, the better, else we spill our gin !! /forums/images/graemlins/smile.gif
 
It's more for when your close reaching. The bow wave tends to rise up, so if you've got a deck sweeper, it can catch the odd wave. Also, with the clew raised a bit, say level with your gooseneck, its fore 'n aft sheeting position won't be quite so critical when compared to a low clewed sail.

Talk to Peter Sanders, first class sailmaker.
 
If you can tolerate the sail changes, selecting the size of roller genoa before leaving the marina perhaps, something like a number 3, which should be about 105% of foretriangle, low clew, close sheeted, can be very efficient to windward. Also much easier to tack than having lots of overlap.
My last boat was always at its best with the racing #3 and full main and about 20kts.
You pays YOUR money....
 
Hi Nick,

I went for a high cut no. 4 on Hana, which seemed to be a bout the right size. Could still sail reasonably in 15 knots of wind and could just about hang on touching 40 knots.

The other benefit was that it was much easier to tack because there was virtually no overlap and the high cut clew made it much easier to see what was coming up to leeward. Jeremy White of White sail made it.

White Sails
 
You're correct that the IJ refers to foretriangle. I was using a bit of licence to differentiate between inner and outer triangles not knowing distance between forestay and solent/inner stay - apologies if I was confusing you. I too support the goose neck height clew for reasons stated and also for forward visibility.
 
Nick, Our boat came with a 150% No.1 roller genoa with a foam luff but it was never much use to windward when reefed. We bought a 100% No.3 genoa with the same luff length as the No.1 but a high clew. (We set it on the roller reefing gear and just try to pick the right sail for the day before setting off.) This sail is excellent to windward in a force 5 or higher and the high aspect ratio makes it easy to tack and gives good visibility forward. We carry it to windward with two or three reefs in the main up to about 30 knots apparent (say force 6-7).
The No.3 tranformed the boat in strong winds, I can't recomend it highly enough. Also as it is exclusively a heavy weather sail you can get it made in heavier cloth than the roller genoa.
 
Nick,

I'd echo the calls for a foil-type jib, long luff and leech, short foot, and the clew up out of the way of waves and spray. Sometimes called a Solent or Spitfire jib. Equivalent in sail area to a conventional number 3. I remember some tough weather on a 41 footer when that sail earned its keep, keeping us up high and fast without being overpowered. It sheeted inside the shrouds for beating.
 
A Solent jib just fills the fore triangle, high aspect ratio, low foot, great for beating but still a big sail. Some would argue that as the leading edge has most effect there is not much point in a larger sail when going hard to windward.

Spitfire is much akin to a storm jib.

Think you need a no 3 or no 4, high cut, but your sailmaker is the expert. At what wind speed does your furled genoa cease to be effective? I have the same problem, but am wondering who goes forward to rig sail and sheets in F5? /forums/images/graemlins/confused.gif
 
Genoa gets furled and ceases to become effective, dependant on a mix of factors:
- wind direction and speed,
- sea state
- presence of the co-owner on board (which takes priority over all else!!!)

I havent taken any measurements, but F5-6 is about right.

I take your point about going foward to rig another sail, but there again people have been doing that since Noah was a lad - just got to have the right gear, and experience.

A more practical answer would be dependant on the forecast. eg if coming back from France, and you have a recent forecast, decide before leaving to rig the smaller sail and use it. If there is less wind, it would be easier to drop it and derig the forestay, than to have to do so the other way round. (I feel like I am teaching granny to suck eggs on this, Keith, sorry!!)
 
You must log in or register to reply here.

Share this page

Top