Not quite
The percentages are not the foot dimensions-they are the LP dimension, which is the "luff perpendicular". This is measured from the intersection of the leech and foot (essentially the bearing surface of the clew ring) to a point along the luff which is perpendicular to this line. Thus a 150% genoa will have an LP of 1.5 X J, or 21'. But these are definietly NOT the foot dimensions.
The foot dimensions for a 150% genoa will vary with the leech length (clew height above deck), but a 150% genoa will ALWAYS have an LP of 21' (for a J of 14').
You have couple of options if nobody here can give you measurements from a sail they already have..
If you call any major loft for a quote, the quoting software will provide approximate dimensions for foot and leech, but are based on some assumptions on luff length and desired clew height (for a furling genoa this will be about 12-20" above the track). I am sure the San Diego North loft will have lots of 35-II genoa designs on file and can give you some sizes, and so can the Chicago Doyle loft.
Or, if any other sailmakers still have one of the old sailplans on file they can scale off the dimensions for you-allowing for your furler if you tell them the height above deck of the lower drum and and your max available hoist (41.5' in your case).
Since the leech length is most critical (I assume you are looking for a used sail), you can fasten a tape to the bottom of the upper drum and hoist the halyard all the way up. Lay the tape OUTSIDE the shrouds (as if it were the leech of a genoa sheeted in) and measure down to the height you want. You do not really want a low clew ("decksweeper") for a furler if you plan on using the sail in a partially furled manner. Low clewed furling genoas do not set very well when reefed. I would shoot for about lifeline height (24" above the track). This gives a good compromise of visibility, reefability, and upwind performance. In terms of fore and aft location for this measurement, you can use a point about 20' aft of the stem fitting. When shopping for a used sail your main concerns will be luff length, leech length, and LP (the size of the sail), and the foot will take care of itself (until you get so big on the LP that you run out of track). I am assuming you are using the outboard track, but if you have an inboard track and this is what you want to use, then measure your leech length to a point at least 1 foot forward of the aft end of the the track-this way you will have some sheeting adjustability.
Hope this makes sense-I just got off a plane so am spun out. Let me know if you have any questions....
S:nerd:
