[cfreeman]

Boy, you sure put a lot of thought and work into this. Nice drawings, I wish I knew how to make those.

I have just two (one too late) comments for you...

1) Regarding #3 & 4 of your "lessons learned"... "smearing" some hardware store 60 minute epoxy isn't the way to seal the core. Most core material (balsa or foam) is not made to take a localized compressive load such as you are producing at the mast base. With the compression of those bolts you're going to break the seal caused by the epoxy and you may end up with leaky core and a delaminated deck. The right way to do this is to use West System epoxy with their colloidal thickener; while you are buying it, get their "guide to common boat repair problems" and look for the "mounting deck hardware" section. Basically, after drilling the hole, mount an allen wrench in your drill chuck (you may need to shorten the short side a little) and use it to shred all the core out of the hole back at least 1/4". Then mix the epoxy with the thickener to the consistency of thick peanut butter. Use one of their syringes to inject it into the space; muck it about so all voids are filled. If you have a fairly small hole like 1/4" or so, take the matching hex bolt with a smooth shank and coat it with a mold release material; I use dry teflon lubricant like Sailkote. Stick it in the hole and let it all set up a half day, then bang the bolt back out. Now you have a nice clean hole with a strong waterproof core of epoxy. No leaks or compression problems there. Now bed your bolts through that. I prefer Sikaflex 295 UV for bedding but there are other options. This technique works great with big holes, like chainplates, too.

2) Look into the Scott Boom Brake for a preventer. Hard to get (they are made in England) and expensive but it's awesome; you can control the gybe with a 3mm line and two fingers. I've used one on the Caribbean to Maine run now and it's fantastic.