Speaking of dismastings I was trying to careen the boat in the backyard to check the centerboard. But, when I pulled hard on the main halyard to get her over the port chainplate back-up actually pulled through the hull, stuck between the hull and deck, and separated a 4 foot section of the hull-deck joint.
There was no damage to my mast or home-made tabernacle other than the AWI sensor and cable which needed some solder, and the mast was still standing.
BTW I'm really pleased with my new tabernacle (mast hinge) having broken 2 of the Dwyer type in only 1 season. It's very sturdy even though it's positioned high enough to leave the boom and mainsail on when the mast is lowered for trailering. And, once I have the safety bolt in it stays up without stays!

I replaced the standard chainplate back-up, on both sides, with a 9" long 7/8" OD stainless thickwall tube. I drilled the 2 bolt chainplate pattern near the middle, then added another set of 10-32 bolts 1.5" in from each end to strengthen the hull-deck joint after I cleaned and re-epoxied the joint. (I had some difficulty clamping the joint and had to install temporary screws along the sheer., followed by filling the holes with a gelcoat fix kit)
I tend to go overboard with repairs but in this case I didn't add the fiberglass clothe to the sheer deeming it not necessary until the joint shows signs of reopening. Not to mention that's a lot more work and time consumed off-water.
My mast is 5.5" shorter than class rules allow, and in my quest to reduce lee helm I am adding more and more rake to the mast. For a few weeks now I needed to wear a helmet since the boom is so low! So, I added 4.5" of wood and a 3/4" wedge under the mast step to get the boom away from my ear. My original thinking was that this is a temporary fix to find out where the rig balances. Being 8" x 3.5" It seems sturdy enough in the for'n aft plane, However, I think the potential athwartships forces could break it and if I keep it I'll make it square instead of rectangular. I do have another mod in there that strengthens it though; a "U" bolt, which is bolted to the deck right in front of the mast with the threads pointed aft so I can clamp the mast at the partners (and it doesn't move!)
Good Luck CCaps