On the water in the bearings issue:
I posted a request for advice about replacing bearings recently, but then I simply regreased the ones I had. I decided that my unicycle has doen a few hundred miles, and that my bicycle used to do many more than that before the bearings needed replacing.
All I did was this:
Drop the wheel out of the frame.
Use a tiny screwdriver to carefully lift the rubber ring out of the bearing unit.
Rinse the bearing thoroughly to remove grit. (using an aerosol spray such as WD40 would help to blast out any grit or dust.)
Allow the bearing to dry.
Add grease. I used motorcycle chain lube which again has the advantage of being aerosol, and which is formulated not to damage the rubber O rings in a motorcycle chain, so won’t damage the rubber seals in a unicycle wheel.
Replace the rubber ring, carefully.
There was no need to remove the bearing cage or the balls.
OK, so maybe a full overhall would be even better, but this worked for me, and got rid of an irritating noise,
It’s a simple job. 20 minutes at most.
As for riding fords. The problems will be:
Hydrodynamic drag on the wheel.
The uneven bed of the ford, shifting under the tyre.
The buoyancy of the tyre, reducing your grip.
Any cross current that might knock you off course.
Drag will ebb much lower if you ride slowly.
You will be less affected by uneven ground under the wheel if you stand on the pedals and ride slowly.
The buoyancy problem will get worse, the deeper the water is, as you attempt to submerge more of the tyre. Look at the shape of the tyre to see how this is NOT a straight line graph. Stand on the pedals to keep as much of yourself out of the water as possible.
Aim upstream to counteract the effects of the current.
It’s easy to say these things. I’ve never done it for real in anything deeper than about 6 - 8 inches. Accept that it is a game. You may win, you may lose.
But do dry the uni thoroughly - most forks are hollow at the bottom and water will get into the frame there. The seat tube is also hollow, as is the seat post. The bearings need greasing. Lots of WD 40.
WDs 1 - 39 were not nearly so good.