I just recently insured my boat for "Agreed Value" through BoatUS
When applying for the insurance, I listed the actual price I paid for the boat, but asked to insure it for quite a bit more.
They came back, questioning why the delta. I explained that the boat was in pretty bad state when I bought it and that I spent quite a lot of money getting it in the current shape (boat physics...black holes..
They said Great, no problem, but please send us the yard bills.
Well, I don't have yard bills, as I did all the work myself.
Here it became a little more tough - They explained that they will except receipts for all the replaced / new equipment I've added, but that labor can not be included - I guess my own labor have zero value....
Well, and here's a lesson for all that work on their own boats - I didnt keep most of the receipts.
I documented in my boat log anything I bought for the boat, but only in my own writing.
They were not happy with this and at first kind of said - Sorry we cant help...
I ended up documenting via photos everything I did on the boat - luckily I did take tons of pictures and videos as the work progressed.
Submitting the photos combined with the list of equipment I bought (with prices), they finally accepted the stated value, and proceeded with issueing the insurance.
Although it was a little bit of an effort (due to my own mistake by not keeping receipts), they generally were good working with, and their quote was quite a bit lower than everyone else I tried.