Hello, I apologize in advance if this sounds like a dumb question. I bought my first boat last year and am selling it due to the fact that I bought a nicer boat a few weeks ago. I've had several inquiries as to whether or not my motor is a long or short shaft. I understand a short shaft is considered to be 15" and a long shaft 20". My motor is a 25 hp Mercury and measures 18" from the top of the transom/mounting clamp bracket to the cavitation plate. Since it is about halfway between the two, I am not sure what to call it. Should I call this a long shaft motor? Thanks!