Hi Keith,
There might be reasons that you've never seen a boat design quite like what you've come up with.
With a barge front end, no bow taper, I doubt that a 10kW outboard could push the boat to hull speed (6.5kts) even at full power. The full rocker will mean that the boat will settle fore or aft when you walk from one end to the other, maybe entertaining at first, but I wouldn't want to live like that. You need more set bouyancy at the ends to create a stable platform.
Personally, I wouldn't be worried about driving into a headwind, I think that your design lasks the power to deal with almost any sort of cross wind. Your boat has a huge side profile. Think about it with a regular ICE outboard. I wouldn't think that a 20hp motor would provide safe navigation in anything but very calm conditions.
But you did say that this is a liveaboard, and as a floating home, it's seaworthyness is not really an issue. Most of the liveaboard houseboats in my area can barely move under their own power and rarely move at all. So if you boat has just enough power to move slowly from one place to another, picking only the most benign conditions, then you should be fine. If that is all that you want to do, then your design should be adequate.
Fair winds,
Eric
Marina del Rey, CA
"It's easy to make something that looks like an airplane, it's much harder to make one that can fly."
--- In electricboats@yahoogroups.com, Keith Jacko <nrixez@...> wrote:
>
> I agree with you about the power. A 4 mph current is not the norm of the upper Mississippi... it's fairly rare. I'd personally feel more comfortable with a lot more hp, but larger format electric outboards are just not available. The biggest I've heard of is an Aquawatt at 20kw (BIG GREEN THRUSTER 80 V 20KW). Still not a huge motor really, unless you're considering the price tag, and then it's ginormous. :)
>
> Incidentally, I'd like to stick with a 48v system if possible. It might not be, but it's a nice-to-have in my mind.
>
> Thanks for the feedback about the hull form. I know having the rocker like that isn't the norm, but it's not nearly as severe as Bolger's designs. (I was using Bolger and Thiel as inspirations for this design; I've heard their boats are very easily driven.) I absolutely agree that one tradeoff with the full rocker is less pitch stability. I think I'm willing to sacrifice that though because I won't be using this on big water. Do you think the rocker as pictured is so severe that it'll actually cause issues?
>
> Cheers,
> -keith
>
>
> --- On Fri, 5/4/12, danbollinger <no_reply@yahoogroups.com> wrote:
>
> > If this was on a lake and you only
> > had to deal with the occasional headwind I'd say that 10Kw
> > (13HP) was enough, but not in a 4 mph river current. I use
> > my Torqeedo on a 12' john boat on the Wabash and its typical
> > 2-3 mph current is formidable.
> >
> > Concerning the hull form, I'd take out the severe rocker.
> > Putting in a flat bottom admidships will give you greater
> > pitch stability, reduce draft and power requirements, too.
> >
>
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