So can a 2hp Honda push a loaded (say 2500#) M-17 at its 5.5 knot hull speed against a 4 knot current? I’m hoping it will because I’m tired of doing the “clean and jerk” with my 60# 4hp Mercury. - Jim M-17 “Spirit” On Sep 22, 2015, at 3:49 PM, Dave Scobie <scoobscobie@gmail.com> wrote:
i'm writing this to assure it is part of the discussions about motor size for the M15, M17, M23, Sage 15 and Sage 17.
these are all displacement hulls that have a hull speed (about 5.2kts for M15 and S15, 5.5kts for M17/S17, and 6.5 for the M23).
the Montomery and Sage hull shapes are not planing type. you may get a little past hull speed but not get the boat on a plane with more horsepower (you will make a bigger wake as the boat tries to climb the bow wave).
so, a larger horsepower motor will not allow you to overcome a current greater than hull speed.
yes, with more horsepower you can overcome wind and get a little help overcoming waves ... but not against current as this is constrained by the boat's hull speed (unless you can get the boat on a plane).
-- :: Dave Scobie :: former M15 owner - www.freewebs.com/m15-named-scred :: M17 #375 SWEET PEA - www.m17-375.webs.com