That was the bottom of my old boat , not been out for years , one hour with a jet wash and it went straight back in , engine service kit was £80 including impeller and that was done more than once with the boat still in the water , just backed it up a slipway and put some wellies on, anode on the outboard looked as good as new, nothing else below the waterline to worry about, did more or less a full refit inside but that was just a personal preference thing , it used hardly any petrol, the Eberspacher used hardly any diesel , the gas cooking and the instant hot water heater for the sink and shower went through quite a bit but overall running costs were peanuts...