"R Swarts" wrote in message
...

I routinely use Minnkota Endura outboards in salt water. I first paint the
lower unit with resin to protect it. The Enduras have only a rotary switch
in the upper unit. I find that for most applications I use only the
highest power setting. This connects the batteries directly to the motor
bypassing the "speed coils" used to resistively limit the motor's power.
If you remove the switch and wish to use only high power, the speed coil
leads can be stuffed into the tube leading to the lower unit and any form
of sealant used to close off the tube. At this point, the motor could be
run totally submerged. If you want speed control, you can extend the speed
coil leads as well as the battery leads, or add your own pulse width
modulating (or other type) external to the motor.

To mount batteries, I generally fiberglass in a footing of some kind and
provide hold down straps anchored to the footings. Two 75 amp hour
batteries would give you about 3.5 hours cruising with a 30 amp motor. At
3.5 mph that would be about 12 1/4 miles. Note that I computed that at the
70% discharge point for your batteries. Not going below that point will
extend the usable battery life.

Good luck on your project, and keep us posted.

BS

nice idea about fibreglassing a foot into the hull... i was thinking about
how i was going to securely bolt a battery box in ;-)

when you say coat the lower unit in epoxy, do you mean the motor itself? do
you cover the entire motor (other than the prop/bearing)? did you coat the
upright shaft as well? running submerged would be a fair description of how
my cat moves through bigger swells.... i know this is going to cost me
about as much as a brand new outboard and have virtually zero re-sale value,
but if i can get a few years out of it Id be happy.

in all honestly, 2x75Ah batteries is huge overkill for me. I cant see
myself using it for more than an hour at a time, but i want plenty of
reserve in case i go out two days in a row, or decide to 'motor' a little
further.

Thanks,
Shaun