ANSWER

Dear Mr Marsh

I doubt that even a Hydraulic Bow Thruster will have a continuous rating to allow its use as the some means of steering, I think the oil will get very hot.

Unless you are going to be operating your narrowboat way outside its designed operating area it will be used in some of the most demanding conditions of any marine power unit. Often driving in slurry, accepting shock loading several times a day when the prop hits obstructions or the bottom, being stopped dead and stalling the engine when the prop jams against debris etc.

Basically it is your prerogative to use any drive and steering system that you choose, but remember that the conventional "over specified" gearbox, packed gland and large diameter shaft has stood the test of time - you see very few true narrowboats with outdrives for good reasons.

I would advise an Aquadrive or Python drive on the shaft, but apart from that I would use the conventional system. Just bear in mind you will be boating in about 2 ft of water, plus another 1 ft of sludge with hard lumps in it - some would exclaim "that much!"

Tony Brooks