hi everyone, i'm new on here and am looking for some advice / hints. i've recently been to have a look at a narrowboat. its at the cheaper end of the market and was built in 1978. i work as a car mechanic and checked the engine over and am pleased with what i saw and having a good, long look over the boat couldn't see any real problems other than cosmetic ones. the seller seemed very genuine and honest pointing out any problems and answering any questions i had fully. however knowing nothing about boats i have said i will meet the asking price as long as it is surveyed first (at my expense) what sort of hull thickness should i consider as acceptable with a view to keeping the boat for around 4/5 years without needing expensive hull repairs? also are there any other points i havn't thought of? thanks in advance for any replies or advice