Our boat went the way of a "CTL" about 10 years ago. Boat insured for $7K, repair estimate around $5K, bought it back for $800, received a check for $6200 from Boat US. All of that was easy.
What was not easy was that the following year we were unable to find any insurer to take us, not one. The "CTL" mark within 3 years prohibits you from getting most any insurer to take you on. You really don't want to go down this road if you don't have to.
I believe that insurers will wave the "CTL" flag if your repair estimate is 50% - 75% of the insured value so keep that firmly in mind. In some ways you may be better off lowering your repair estimate and just eating the difference - so you can still get insurance.
In our case I could have, and did the repairs a bit cheaper than the estimate. We replaced our roller furling with a new Furlex 101 and a new genoa from doyle. New bow pulpit as well. We also had a section of hull/deck joint that was ground away that I ended up repairing myself. I could not find a fiberglass person to commit to doing the work. I believe that even if I did find someone it would have taken twice as long as it took me since the summer is their busy season.
My suggestion is that you do the fiberglass work yourself and don't include most of the cost for that in your insurance claim. It is not very difficult work.
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Pictures of damaged area(s) might help.
But no, I don't think you made a mistake by reporting it to Boat US. See if you can work it out with them whereby your boat is not "CTL"d.