Same experience. Tohatsu 5HP 20" 'long' shaft and it cavitates significantly when I go to the bow. If I go forward in a steep chop, it will get airborne. I'm pretty sure my old Evinrude 6hp swam a little deeper, though I don't know how much. 25" would definitely make for a better cruising engine.

:: I've been using a 20" longshaft and it frequently
:: cavitates if any weight is forward or in moderate chop.
:: I tried what I think was probably a 25" long shaft and
:: it was vastly superior in performance and always stayed
:: deep.
::
:: Has this been others experience?
::
:: :: I have been told a Santana needs a "long Shaft" motor.
:: ::
:: :: I seem to see many short shafts on CL and EBay, but
:: :: fewer long shafts. And the fancy new propane from Lehr
:: :: only comes in short shaft.
:: ::
:: :: Has anyone ever used a short shaft motor? Will it work?
:: ::
:: :: Also, what about the longer short shafts measuring in at
:: :: 18 in?