Dock fees, fuel repair costs, insurance, and the salary for a licensed captain if your Yacht is over a certain size add up. Boats are not cheap. Even "small" (anyone with a automobile license can drive it) 40ft ones. My buddy's family owns a 45 ft Yacht and the joke at the harbor is BOAT = Break Out Another Thousand. Where they dock it they pay $10 per foot per month in dock fees which is cheap for the area. 5 miles down the coast it's $30/foot/month.