I have a 115 Evinrude w/ a 20" shaft mounted on an '86 Bayliner with a 25" hull, this leaves my cv plate about 3" above bottom of the hull. My question is would a fixed jack plate mounted upside down be ok or do I really need to spend the extra $300 to get the shaft extender?<br />This is the jack plate I'd like to get - http://www.thmarine.com/product.cfm?PRID=22