Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
For conditions that will involve any pitching and rolling (chop or boat wakes), the ideal is "Extra-long", also called 25" (although the actual measurement from the top of the bracket to the plate above the prop is generally a couple of inches more than that). On a 25' sailboat, there's no reason to go shorter (such as "Long") unless the motor you want doesn't offer XL. 8 - 9.9 hp is also recommended, although some folks on small lakes or who never use the motor for other than getting in and out of their marinas have been satisfied with 6 hp.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
At least 20" (long shaft) would be adequate on an inland lake with smoother waters; or, better yet, a 25" (X-long shaft.) would be good, especially on coastal waters or a big lake or bay where the waves get bigger. Rarely do you hear anyone complain that the shaft is too long. I've heard there's a 30" XX-Long shaft, but have never seen one. That might be taking the principle a little farther than necessary.
Steve Milby J/24 "Captiva Wind" previously C&C 35, Cal 25, C25 TR/FK, C22 Past Commodore
I've heard there's a 30" XX-Long shaft, but have never seen one. That might be taking the principle a little farther than necessary.
I've seen those in the 200-350 hp range--which is a little more than necessary.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.