
Hi Steve, I have no experience of the Horizon, but on our Sigma 33 the indent line in the hull was the designed waterline. How does it compare with all the antifoul etc you have been taking off?
In any case, where the waterline should be is not an exact science. Depends a lot on whether water tanks are full, where anchor chain stowed etc. Our boat comes out of the water nearly two inches when we convert from cruising to racing mode. This is one reason why it is a good idea to paint your boot top (the band above the waterline) with hard antifouling (eg Trilux) so that if it is partly in the water some of the time it doesn't matter!
Good luck with the hull work. It will be worth all the investment in time and effort, as the boat will be super fast and slippery next year!