I Din't say anything about a Keel cooler...………..And the boat would do the same speed as any planning luxury yacht or sport fish . Where did you get 8 knots from? just make it up? Engine builders got you,for now, until a better system is built. They can charge outrageous prices and demand crazy maintenance schedules. I'm also been looking into propane/ Electric. I know propane doesn't have the energy density as #2 fuel oil, but would remove all problems with carbon & soot and nothing grows in it.