A boat seems like a tasty and easy target for anyone interested in theft.
At the marinas, you just untie it, and it floats away. On a trailer, you just hitch
it up to your pick up. A yacht in an area of pirates = 24 hr worry.
In the western days, the horses would get tied to the hitching post while the owner went for a drink, or in the store. Comes outside - horse is gone !