Since it's a little slow right now, I thought I'd ask for the expertise of the mastmath whizzes out there. This will require higher mastmath skills, beyond my competence, maybe even up to eighth grade level.

I'd like to rig a mast-raising system that can be used not only to initially raise and lower the mast, but on restless water also. Regardless of which method I end up with, I'd like to rig a couple of baby stays (actually shrouds) on either side of the mast to steady it while raising or lowering. I've already made them and they connect 62 inches up the mast (no, I don't remember why, but it must have had something to do with my first errant calculation, below), but I was never able to find the correct placement for the other end, on the cabin top.

Not to get off on a tangent, but my first mental attempt was to put them in line with the mast and perpendicular to the centerline, under the assumption that the mast base is the center of a circle and the baby stays would essentially trace a radius, but no, since 1) the anchor points of these shrouds (on the cabin roof) are not in the same plane, and 2) the cabin roof slopes away. So the next brief thought was to put them in line between the existing shrouds and the mast base, but no, since the existing shrouds don't stay tight from mast up to mast down.

I know it could be calculated by someone wiser using the degree of cabin slant (a slippery slope?), but can I find the points by fastening the baby shrouds to the mast and then drawing an arc on the cabin top with a pencil attached to the other end, first with the mast up, then with the mast down? Seems to me where the two arcs bisect would be the common attachment point to the cabin roof. Won't somebody give me a sine?

I kinda tried to estimate it roughly once and I believe the point worked out to be several inches forward of the mast, which makes sense when one thinks of how the existing shrouds, which are only an inch or two forward of the mast, loosen as the mast is dropped. They're also MUCH lower than the mast base.

It makes sense to me to make the anchor points as far away from the mast base as possible to be most effective, and in order to prevent my having to drill more holes (i.e., leaks and toe stubs) in the cabin top, to maybe clip them to the handrails at the edges of the cabin top, since they're only in use for short periods, anyway. The ones I've made may be too short, but it would be worth re-making them or adding wee turnbuckles to fine-adjust and/or add length.

Can I assume that if these baby shrouds are tight at mast full up and mast dropped that it will be tight enough to prevent the mast from swinging sideways TOO much throughout the raising/lowering arc? Or, dast I utter it, is it possible that never the twain shall meet, and there is no common anchor point on the cabin top?