Human Powered Drive - Suggestions?

Yet another pedal boat question from me. I'm pedalling (hopefully) the 364 kms of the Nantes - Brest Canal in a 6m Kayak-alike boat.

The usual human powered drive is to have some form of large propellor dangling under the boat ready to snag on things, get in the way when beaching and fill up with weed.

A lot of the canal is navigable and the locks all open and close. Some of it has weirs with canoe-shutes to slide down and some of it (about 40 kms) looks like this



Then there's this



Hydro-electric barrage to get round.

So you can see why the dangly prop drive isn't my fave idea. I've looked at the Hobie Mirage Drive patent HERE and the latter looks better, but can anyone think of any other way to drive (and don't say paddles)

 

electric motor and generator? Human electric propulsion

A electric ac generator with 4 poles and a electric motor with two would incresea the proppeler rpm and therfor reduce the proppeler diameter and it could be easier to fitt inside a nozle. Electical reduction off the rpm would ad less friction than a gearing system.

Could work, but it's 3O'clock in the moring here and I did not think to mutch about it.