I don't know how marine insurers will treat this, but give you this as a place to start looking for information. Boats 9with engines) and cars are both often treated as "motor vehicles" under state laws. Each state obviously varies.
In some states, when the insurer "totals" a vehicle they are supposed to take your title (have it endorsed over to them) and then issue a new "salvage title" when they sell it for junk. That costs money and takes time, so sometimes they simply ignore the title laws and say "We'll sell you back the vehicle for $$$" and the title changes never get posted or made. In this case buying "back" your vehicle can be simple and good.
But when things are done properly and a salvage title is issued, EACH STATE has their own requirements for how, or IF, a salvage title can be cleared and a plain new title reissued, if at all. In some states they require an inspection at a special location, and with cars they require them to be flatbedded in and out of the inspection point so the process becomes expensive simply in transport fees. Ignoring the inspection fees.
With a boat? You would need to check your own state laws, see if they treat boats as "motor vehicles" or as boats. Whoever registers and titlesboats in your state (DMV? DMR?) should have this process documented on their web site. DO NOT TAKE THE WORD OF SOMEONE ON THE PHONE, you want to ask them "OK, what is the statute, where can I see the actual written laws" because often a clerk answering the phone misses a few fine points.
"Cosmetic" totals (i.e. lots of paint and cabinets) may be treated differently from structural or safety condemnations too. So...those are the things you need to look at.
And yes, my car was once stolen and stripped and the insurer said "Needs too much stuff, we're gonna total it." They did, I bought it back, there were no structural or safety issues and the title stayed with me the whole time. No problems reinsuring it, they just wanted to see that it was all back together again.