Larry makes a good point.

What outboard do you have? Maybe an alternator can be added to it.

At the moment i've got a honda 2HP 4 stoke. I'd hate to fit an alternator
to it for double the weight and half the power ;-) Ive been looking over
the last 3 months for a second hand Honda 9.9 4stroke high thrust,
preferably one only a couple of years old. Honda dealers in sydney are
trying to sell these new with all the forward controls and without a tiller
for AU$3,300. Id be pretty happy to get one a couple of years old in the
plain vanilla tiller control which has an electric start and an alternator
for maybe AU$1500. Then i would have a bit of power and i can use the 2
pony on my dinghy, and as a backup motor.

Shaun