Part of the insurance surveyor's job is to estimate the value of the boat. The value given by a surveyor
is expected to include his/her consideration of the market. The good ones have access to sites that provide the selling price, not just the asking price. I guess not all surveyors do their job.
On my last survey
, 2 weeks ago, my particular value went down 19% from 5 years ago, for a properly maintained boat, suggesting either one or the other surveyor
made errors or the market for small catamarans is down 19%, or the increasing age makes a difference, or all of the above.