[cucubelu]

I found a nice definition on Yahoo xD

A ship is a commercial vessel such as a passenger ship, a freighter or a tanker. A boat is smaller - could be a fishing boat, a dinghy, a sailboat, a row boat, etc., and could actually be fairly large. A yacht is a personally owned pleasure "boat", either a sail boat or a power boat, but is not a ship

So basically as long as it is a recreational vessel it is not a ship! :p

Source: http://answers.yahoo.com/question/index?...402AAWBRbj