Colin,

Love your clever way of finding the CLR with a piece of string.  Guess the some can be done to find the CE of the sail, if the wind was perpendicular to the boat.

I think I am correct in saying: this method, as with balancing cut-outs  finds the static CLR / CE.  With a low aspect keel the CLR underway is actually much further forward.  Same for a low aspect rig, so perhaps one cancels the other.  Though mixing a low aspect keel and a high aspect rig (or visa-versa) may lead to misinformation.

James, Be not discouraged,

If you do not have a drawing of the underwater profile of your boat you can still get the information you need to make a new sail-plan. The bit of information you need to know is the point on the centerline of the boat around which the boat turns (the CLR). For a clear discussion of the problem see https://forums.paddling.com/discussion/1452776/the-center-of-lateral-resistance The discussion there concerns canoes but is applicable to all sizes of vessels.

In the case of a yacht, the CLR can be found by pushing the boat sideways away from a dock some 8 to 10 feet then using a single line to pull it back toward he dock. By moving the pulling point fore and aft along the centerline of the boat one can find the for and aft balance point of the boat. That point is the CLR.

If you follow Arne's system of locating the CE of the new sail-plan on the same fore and aft line as the previous sail-plan (the Jr sail's Center of Effort will be lower than the Bermuda rig CE) the new JR mast position can be found. Luckily, it is within the tradition of JR masts to be canted fore-and-aft to suit the needs of the accommodation plan. And that is another plus for JR.

Colin King

James, in saying that you're not ready to DIY it yet, do you mean that you want to hand over the whole design and build process to a professional? If so, there's really only been one in the UK - Sunbird Marine, with Robin Blain making up rigs to designs by Alan Boswell. But that route is going to cost a great deal of cash.

I believe that now that we have this forum, it's entirely possible to start from zero; to read Practical Junk Rig intelligently; then come here to ask questions about things you don't understand; even to get the basic outline of a rig designed for you on an amateur, no-liability basis by several of us who have experience of doing just that. As you'll have seen, we're currently advising James Hleba on a rig for his boat, which happens to be quite similar in type and size to yours. If you're practical, it's not such a hard job to put together a junk rig. Of course, the job can be speeded up by getting some items professionally made. Exe Sails and Covers (back page of the magazine) will make you a sail, if you don't want to learn that skill. The Auminium Lighting Company are now getting used to junkies asking them for bare tapered aluminium poles that are most of the way towards getting a good mast. We have sources for everything you'll need. We're able to provide advice from skilled amateurs on installing rigs.

To get us started, we need more info on the Elizabethan 31. Sailboatdata.com doesn't give an underwater profile, which is needed to establish the CLR - do you have a drawing?