yep, took it on a river in Normandy near Carentan last year.
This is the group waiting to go in the water, i am the 3rd one in - I think there were about 8 or 9 of us that went 'schwimming'
Here's me coming out of the river
And what you cant see from the above is that i was being towed out. I got in ok, sailed around for a bit using the wheels for propulsion (wide and deep tread ok for going with the current). Then needed to start the prop which you do by stopping the engine, pushing the prop onto a dog clutch driven off the crank (in the first photo above, you can see the rod which you use to lower the prop onto the clutch), restart and away you go. However, my 'prop man' failed to engage the prop drive 3 times and then because i had a charging issue, it wouldnt start on the 4th attempt.
But as you can see, she floats with 4 adults aboard although at this point, i wasnt talking to my prop guy (leather jacket) holding him responsible for the mission failure. I may or may not already have sworn at him profusely at this point but he is Canadian so he is used to it.
On return to UK, had the generator rewound and then during the check over, discovered my problem was actually a solder connection in the regulator had cracked apart.....
All schwimms leak to a greater or lesser extent so there are a number of drain plugs in the bottom. The cars were designed for crossing rivers rather than tooling about for an hour on the water so if you are afloat for any length of time, it gets quite damp inside! Some people fit bilge pumps but then you have to convert to 12v as there are no 6v pumps available apparently.
They are good fun though!