jack plate for motor

[skinny]

my current hull is one of older design and shallow. I also believe my motor to be long shaft. it seems to me there is alot of motor stuff below the transom. I'm looking for different hull and for mean time was thinking maybe I would build a jack plate for the one I curently have. this made me think how mch should be below the transom. can anyone help

[Fisherman]

Transoms are generally 15" or 20" give or take an inch. Motors are easily measured, from the top of the cavitation plate(flat "wings" either side and above the prop) to the bottom edge of the motor mount that actually touches the top of the transom on the boat. The cavitation plate is usually located even with the bottom of the hull to about 1 inch below. Some experimenation is done to achieve best performance, each boat is a little different.