Hello again Alctel:
Yes, deciding on details of new sails is a vexing task! As you, I also posted questions on the forum -- about a year ago -- when I was weighing the options.
Given that we have the same boat, below is the outcome a new head sail which I did order. For the previous 9 years of my ownership, the head sails I used were a combination of a 1980's made (but not OEM) 135 Genoa; and various DIY mod's I did on second-hand sails.
Before going further, note that I sail on San Francisco Bay. Wind velocity is all over the map. But foremost is the sail must be good for almost always 20+ kts.
I don't talk in 100% or 110% terms because even though I got through two years of college calculus (albeit 40 years ago and I did hit the "Peter Principle" wall in the course called Calculus of Vectors), in respect of jibs, "%" while useful , doesn't really reveal a lot to me since other variables are also in play at the same time.
The dimensions that you might consider as a starting point for your new headsail, based on what I and my sailmaker decided on are:
- Foot length = 16.5' = the clew position winched snug in little/no wind (i.e. flat sail) is about 4-6" aft of the center shroud.
- Leach length was designed to achieve a clew height of 3'9" above the toe rail when winched snug say on a close-hauled reach. This was a compromise of performance vs. day sailing comfort: Leans a bit more towards a "Deck Swept" cut vs. a "Yankee Cut". Of importance to me on busy San Francisco Bay is to be able to see under the sail by bending my neck down -- even when heeling. In actual practice, the 3.9" was a good decision.
I have not given you my luff and leach lengths. That is because I don't know how high above the deck your furler drum and tack point is. (Mine is higher than most.) Other boats will have the drum height much closer to the deck. Also, I don't know how your mast head blocks and sheaves are configured; or what brand of furler you have.
My new jib has been good on my boat in our frequent 20-30 kts winds and I am very pleased with the outcome. I find that my Cherubini Hunter 36 in these conditions sails very well and is balanced with the jib full out and with the mainsail on my second reef. To me the "full out" jib is important, because even with a foam luff, a furled jib doesn't perform as well. This particularly the case if the jib is large like a 135-150% for which quite a number wraps are needed on the furler if the wind becomes even moderately strong. Back to my jib, in lighter winds with the mainsail fully raised (doesn't occur often actually), it is still large enough. A larger dimension head sail undoubtedly would be better. But problem is I don't want to change sails from day-to-day. Also I opted for a heavy weight sail cloth, so as to minimize cloth stretching by SF Bays' strong winds. Because of the jib's weight, it doesn't shape as well in light winds as would a jib with thinner sail cloth.
Hope this info helps you get started with a new head sail. But as suggested by previous respondents, you must talk to the sail lofts in your area. They know what sail configuration is best for the region's typical sailing conditions and can recommend the best choice of sail dimensions plus the fabric type and weight.
If you do want more details about my head sail, let me know.
Regarding a new mainsail, again its best you and a local expert talk to tailor it to your typical conditions. But things I have have considered: Leach length should be such so that the sail hangs with a safety margin above people's cockpit standing head height and to clear the bimini if you have one. Not only for the full sail, but for each reef point. Back when our boats were made, the style often was for the boom to be hanging even below vertical. My OEM sail did this. At my 6'3" height, it allowed the boom to hang about my temple level. Dangerous! I cut my subsequent mainsails' leach/clew so that the boom level would be a couple of inches above the top my bicycle helmet -- which I wear for safety. For mainsail reef points, I would suggest that two are enough. You aren't racing. Wind conditions I expect in the the Juan de Fuca Straight and the the numerous sounds/bay/straights are variable from minute to minute, so really it's not practical to choose a reef point for every 5kt's of wind velocity. But make the reef points deep enough that they have real meaning. Our boats don't have deep keels so they are sensitive to increasing wind velocity. The first should reef point be good for stiff winds. The second good for almost gale force winds. It is much easier/quicker/safer reduce the sail area by the furling jib than frequently changing reef points on the main sail. And also as this forum's sail trim expert Don Guillette has conveyed often, for our masthead rigged boats, the jib is the primary "engine". Not the mainsail. That is why even in 25-30kt winds, I will set the mainsail at the second reef, but the jib is full out.
I second Jim's idea of talking to your sailmaker, they can explain the options from their experience. I had mine both re-done in the last several years and am happy I took their recommendations for the local Chesapeake sailing conditions.
