RE: Single v/s Twin
I've looked at that boat ad myself, trying to figure out what the after section is for; I'm guessing that's where the alternator/generator is located. If you look closely at some of the photos, the electrical panel is still labeled Ocean Alexander 423 Classico. Some one sure spent a lot of bucks for not much return - no increase in living space, and a very modest improvement in fuel burn. i don't see how there is a payback for that investment.
Eric, I wouldn't be surprised if our hulls are very close in form from the sheer clamp down.
I recall that your 44 is a 2 foot extension of the similar 42 model, and the 423 classico series immediately followed the production runs of your model.
I don't have floscans so my figures are calculations. I have an actual speed vs RPM curve for the boat, and used the Caterpillar fuel burn specifications for the 210 3208.(2.5 gph per engine at 1500 rpm, for example). Empirically, the fuel consumption calculations are pretty much borne out with total fuel consumption when I fill up. I have 2:1 gears and 29xx21 props.
Is there a 22% improvement with the diesel electric? I'm willing to give them the benefit of the doubt, but again to what end - the economics don't justify a repower, in my opinion. Using some generous numbers, let's assume engine time of 150 hrs/yr (I think a lot of boats average less than 100 hrs). also Assume a 10-11 mph cruise speed average (7gal/hr for me), and fuel at $3/gal. So I would burn 1050 gal/yr. A 22%savings then is 231 gal at $3 is a savings of $693 per year. $700 per year would support a loan value of less than $8000 at say 6.5% interest over 20 years - not close to what must have been spent.
But, give this owner credit for trying to push the envelope on propulsion systems.