Interesting point about designing the whole system to suit electric power. 
With regard to propellers, are slow moving, large diameter two blade propellers the best? That is significantly larger, perhaps 5x or more.  Human powered vessels with a tiny power input use propellers of similar size to small outboards. 
This would need not only the power system, but the hull designed to suit.

I will certainly share my experience with this new motor as time goes by. Even if it's a failure, it can serve as a bad example. 

I think it's part of my DNA to try new technologies. My paternal grandfather bought the first refrigerator in our home town. The first boat I built was a trimaran. Multihulls were scarce in those days. (1969) Then I got into ferro-cement. I could write a book. (Please don't ask for details.) Then came the junk rig and wood/epoxy construction.

All I had left to do, to recommission my YSB12 Yanmar diesel, was to hook up the new control levers. My techie had brought my electrical and engine systems up to par and here I am changing course. At least, a good proportion of the money spent will not be forfeited since much of his work will dovetail into the new system. I'll advertise the motor online (Kijiji). The buyer will have a complete kit for restoring a vintage Contessa 26 or something like it. 

The electric motor was picked up for shipping yesterday. I would suggest, if you have technical questions at this time, to visit the company's website (electricyacht.com). I have purchased the model: QuietTorque 10.0 Sport Electric Motor 

Jan
I am afraid that if you wife struggles with starting a 5hp 2-stroke, she will also have problems with the Tohatsu 6 Sailpro. I have one myself. After I bought it, it wouldn’t start, so I took it back to the shop. Then it was demonstrated for me how it is done: A really long and fast pull, lawnmower style, was needed, much unlike on former 4-strokes I have had.  It appears that the maker of the motor has geared down the recoil-starter, possibly to avoid complaints about nasty kick-backs, which 4-stroke engines can produce.

I modified my starter chord with a fool’s purchase, and I now find the engine to be reasonably easy to start, and from then on it is dependable, and can run forever at idle speed without dying.
Maybe the outboards from Honda or Yamaha are easier to start? I would not buy any of them until they have demonstrated how they start.

Arne

PS: If you move up one step, to 2-cylinder (8-10hp) engines, you can have electric starts...

PPS: If you convert your boat to a junkrig, the risk of falling overboard is much reduced, as you will rarely have to leave the cockpit. In addition, if one of you should fall over board, the JR makes it easier to go around and make a pick-up, since starting and stopping is so easy with a JR. After doing a bit MOB practicing by tossing a fender, tied to a bucket, overboard, you will soon find how easy it is to do the man-overboard manoeuvre under sail.

David wrote:

Well Jim, all us 'old diesel heads' will await with interest for the outcome of your conversion. A good diesel installation can be relied on when the going gets tough. But they come with complications, so if electric motor can perform the same job consistently and  reliably it can only be a good thing. I remember being very surprised at the minuscule dimensions of the electric motor in mehitabel  so certainly a clean tidy installation.

... until you add in six x 8V or eight x 6V golf cart batteries and a big controller.

I did look at the possibility of an electric outboard motor on the little catamaran I am building, but I do not think I can provide the battery charging capabilities on such a small yacht,  so it looks like a small 4 stroke petrol outboard is the only practical solution. Not to mention the fact that a good electric outboard is many times the cost of a petrol outboard.

Oh, how I wish that electric propulsion was a sensible proposition for Weaverbird - I will never be a 'petrolhead'! I would never want to go the hybrid route, building in the problems of an ICE, as well as the costs and complexity of an inboard electric installation, but with sun and wind power in place of fossil fuel, I could be persuaded about a small outboard. Financially, it never will be sensible, but practically, the numbers are beginning to make sense.

 Nestaway Boats is a good place to compare four direct equivalents: Suzuki and Lehr 2.5HP petrol/gas, Epropulsion Spirit and Torqeedo 1103 1KW electric.

Photonic Universe is a good place to look at solar panels, wind turbines and controllers.

In practical terms, it would appear that an Epropulsion Spirit would fit into the well of my Hunter Duette, and more importantly, could be fairly easily lifted out of the well  and stored, when I'm at anchor or on a long passage, which the current Tohatsu 6 can't.

A 250 watt solar panel could be fitted as a kind of bimini, where a full width sprayhood normally goes over the companionway. With a 30A MPPT controller to make the most of this and my existing 100 watt panel, I think I could get the equivalent in performance of a 2.5HP petrol or propane outboard, with adequate recharging, at a "trifling" 3.3 times the cost. I found a Suzuki 2.5 too tricky to manoeuvre with, having only a F-N shift low down on the wrong side. An electric drive ought to be easier to work with, when coming alongside.

Anyone looking for a secondhand Tohatsu 6 Sailpro?!

I would not hesitate to go offshore with extended cruising in mind with the set up I have now. The shore is the hard part. The electric motor is usually motor sailed off of the solar panels when every one else is ghosting with a big genoa or just motoring. The second use is to get in and out of the harbor in traffic.

  I have not needed maintenance other than cleaning the solar panels and have had complete reliability.

  ...... my large 2 x 6 volt Surrett (rolls) house batteries are still going very strong after 12+ years of use.

  I think you would really appreciate the switch.

I went back to 2011 emails and found that you and I had a long discussion about electric power. Some photos too. I'd almost forgotten... But not subconsciously. :-)

It's good to hear from someone who's "been there, done that." It's encouraging.

About Surrette. Things have changed! - If you Goggle Surrette Battery Company Ltd. you will get ROLLS Battery Engineering. Surrette was bought out by Rolls-Royce but later sold back. They still use the Rolls brand name. Go there and click DISTRIBUTORS and you'll find a fair number in North America, especially the US west coast. There are others scattered about the world. You can find them in New Zealand. The factory is located in Springhill, Nova Scotia, about 110 miles from my home in Halifax. By Canadian standards, that's next door.  I've been directed to one of their distributors, in Pictou, N.S., Nova Sun Power. They have given me a quote on their 6V, S6-275AGM battery. I will order them (8) in the Spring, next year, allowing time for manufacture and delivery.