Wow I'm envious. I don't rate Coast Guard officers in my crew!
Glad you survived this one without damage to yourselves and with your kis experiencing two capable parents in control.
The kind of damage to your shroud is super typical for sailboats of any age. Stainless steel is given to crevice corrosion, especially in the presence of salt. Common locations are just as in your case, the top of the turnbuckle, where saltwater can pool and keep out oxygen (the latter helps the stainless steel remain stainless).
It's worth repeating this as a warning to others: go and replace your standing rigging, definitely after a decade or so if used heavily and on the ocean. In the meantime, inspect, and look for any signs, like slight staining or cracks (in chainplates/turnbuckles).
You can get replacement standing rigging for the DaySailer from DR Marine. Feel free to mail or call them if you can't figure out what to order.
Now for the damage to your mast. It's actually not as bad as it seems. (You might find that suprising).
The bottom part of your mast isn't really acting as a mast - it's simply a compression post. You could replace it by a 2x4 and as long as the tabernacle is attached to the top, the top part of the mast wouldn't be any wiser.
So, you have a number of options.
- You could saw off the top 1" or so off the top of the damaged lower part, drill new holes and reattach the tabernacle. That would leave your mast short by 1" and you'd need to get shorter stays. And the boom would be lower as well, reducing the space for a vang.
- Same as previous, but you'd add a "shim" to raise the bottom of the lower part by the same amount you cut off at the top. Any type of corrosion/rot proof but incompressible material will do. The challenge may be in the details of how to connect the mast to the shim and the shim to the mast step.
- If this a Dwyer mast you can supposedly order mast extrusion by the foot. You could rebuild your lower part that way (you may have to transfer any bottom cap to the new extrusion. That's more expensive than adding a shim, but there's less to figure out. @Alan just gave you the link.
- Get an entirely new mast. Yes, it's an option but, why? I can see it, if you wanted to use the occasion to switch to a single piece mast, but then the reason would be that, and not the need for the repair.
I hope this short list gives you something to mull over. I wish you good luck with a speedy repair and with getting back on the horse and out on the water again, soon. (Including your wife and kids, and for a good time, next time).
This kind of thing does happen, to the best of us. Happened to some of my most experienced friends when they borrowed someone else's boat. That must have been an embarrassing conversation with the owner; but they are all still the best of friends. I have a single piece mast and managed to bend it by attaching the shroud incorrectly to the chain plate and not spotting that. It bent the clevis pin allowing the shroud to come apart. In that case, we were able to reconnect the shroud, pulling against the bend, and sail home. (I always have a spare clevis pin on my key chain).
So, you are in good company. Let us know which option you've decided on and how it's progressing.