Tell them about all the extras - Most companies sell products by appealing to our desire for that little bit extra. When you sell your boat be sure to mention things that are included like radar, downriggers, fishfinder etc. My wife once bought a car because the front seats swiveled round so you could have a picnic, even though we only use this accessory about once a year. It could make a potential buyer choose your fantastic used boat over a shiny one in the dealer but with none of the fun bits.