Rob,

DEPTH OF WELL

  Since the motor isn't going to be steered, I'm not sure the depth of the well is going to be an issue.  Fuel and electric lines won't mind going up and down a few feet.

  As for rope-starting if the starter battery dies, I'd put a snatch block on the side of the well to allow the starting cord to be pulled straight up while the motor is down in the water.


HITTING SOMETHING

  What to do if you hit something with the motor is going to be an issue with all motors, electric or otherwise. 

  The sled system would probably be the most forgiving, particularly if you put a propguard on the bottom to increase thrust and protect the propeller.

    http://www.ronhalemarine.co.uk/superbasket/product/151/Prop_Guard

  [Side note: I have one of these on a planing dinghy with a 20 hp Honda and am very happy with it.  My top end speed is about the same as before, but the increase in thrust is amazing.  I actually bent the trim bar on the motor before I learned to be more careful with the throttle.  As a result, I can now plane a 240-pount boat, with 200 pounds of payload, at 1/3 throttle.  It used to take 1/2 to 2/3 throttle. ]

  However, I want to be able to collapse the boat while on the water with scissors beams, I worry about keeping the prop in the water in choppy seas, and I definitely don't want to expose an outboard to abuse from the sea.  Though the Wharrams have used sleds for decades and I haven't heard too many complaints.

  One option might be a longer well that allows the outboard (with propguard) to kick up if it hits anything.  You'd probably need an extra three feet to get the foot up mostly out of the way.  Is that realistic?

  In general, my guess would be that the motor is only going to be down at relatively low speeds, in which case there should be time to stop after the rudder(s) kick up before hitting the propeller, which probably only needs to be right below the hull.  But there's something to be said about being prepared for the worst.


NON-OUTBOARDS

  I'd love to get that electric thruster, but I'm not sure I can envision spending six times as much as on an outboard.  I don't particularly like the idea of a gasoline outboard, but that said, I'm not sure I'd be willing (or able?) to pay for the alternative.



        - Mike
 

 

Problem for HP in using a well in the hull, it would be 6ft deep.
Thats a 4ft travel for fuel and control lines..
Rope start the engine? has to be all the way up to the top
and what happens if you hit something with the deployed motor leg?

Outboards have some features that are tough to compete with
and you might not need much more than what some people regard as dingy power
on a $ for $ basis its probably the best way to go unless someone figures out a cost effective electric system
and only when you can use the other features electricity can provide you

__._,_.__