If you can hydrofoil with a small sail then a it obviously does not much power to do it :
On May 17, 2012, at 10:24 PM, Scott O'Hearen wrote:
Company website is down. No photos or videos of craft in operation that I can find on the interwebs. Seems like it needs more hp to lift hull out of water just by looking at it.
From: KEN <rekkamurd@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Thursday, May 17, 2012 10:55 PM
Subject: Re: [Electric Boats] Re: hydrofoil 100 km range at 4kts (or 7.4kmh)
From: Eric <ewdysar@yahoo.com>
Subject: [Electric Boats] Re: hydrofoil 100 km range at 4kts (or 7.4kmh)
To: electricboats@yahoogroups.com
Date: Thursday, May 17, 2012, 9:23 PM
Hi Ken,
I based the potential speed on using Torqeedo's data concerning their high pitch prop. Maybe the max range comes at a speed like 10 to 15kts, but at low throttle, the Torqeedo won't spin fast enough, regardless of the load. In any case, they didn't really say, one way or the other. To all of us that know something about electric boats, it seems like an important piece of information. Just a simple statement of what range at what speed would be nice. To 99% of Gizmag's readership, it doesn't really matter. At least when an auto manufacturer says 36mpg highway, you know pretty much what that means.
But the article does propogate the myth that electric power is more amazing than it turns out to be. Because of the impression that articles like this give, uninformed people believe that one should be able to replace a $10,000 diesel with a $2000 electric drive including batteries and their boat will run all day on a single charge. If this inexpensive little hydrofoil can go 55nm at high speed with a tiny battery pack, building an all electric cabin cruiser with a 200nm range on a single charge should be a breeze. Come on, we all know that electric conversions are cheap and easy. ;)
Eric
--- In electricboats@yahoogroups.com, KEN <rekkamurd@...> wrote:
>
> I like it, and also totally agree with Eric, as well as other comments about the item
> (on the article) and its short range.. thats a bummer.
> Â
> different materials cutting the price in half would be a good start, it wouldnt take much of anything speed increase for the small amount of weight it might gain.
> Â
> it comes with solar panels to charge it.. excuse me, whoopity-doo to that!
> if you're stranded someplace a couple little panels are gonna take forever to do anything for ya, and they're not cheep either, if I were in an emergency situation I think I'd rather have a pedal powered generator, which could also be used at whim for extended range running.
> it'd probably be cheaper and more practical, what if its dark out or theres clouds?
> thered be losses of course, but with a flat battery you might be able to pedal 3 mph, and if all else fails does the thing come with a set of oars?
> Â
> I still like it, think its plenty cute, and it has lots going for it as a concept, smooth riding in choppier stuff in a light craft, definite bonus. the range thing.. at its max efficiency speed, is that 100km with 1 or 2 aboard? a few stops and starts is probably gonna cut the range down lots in a hurry, I'm sure shoving it up onto its foils is a big hit to its battery every time, once its up it can be fast-efficient.
> Â
> tough call about applying torqueedo's specs to a craft like that, once its UP it might only pull "X" amps to do 14-15 mph, its a very different kind of load, lots less drag.
> -aint tryin to pick on ya Eric, I dont have a clue what its really gonna draw at different speeds once its lifted to ditch all the hull drag. they make the claim that its foils underwater resistance is "less than air", so it might approach the drain seen by electric mopeds, they can do 15-18 mph on land without a lot of current being fed.
> I sure agree about the promo being misleading many ways.
> 25 mph for 22 miles and POOF, wouldnt be very nice!
> Â
> again.. I dont know, if it can go 35 miles at 15 mph, I'd be pretty impressed,
> but please dont ask me to try to translate volts and amps into Kwh's etc lol.
> Â
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