Hello everybody, and thank´s for your interest!
Never meassured the ice but I guess 2-3mm.
The engine sound was a nice surprise when I first looked at the edited video. They are slowed down on the Youtube editor, looks more realistic ( and sounds! ).
No paint at all is lost, and no damage what so ever to the plastic prop. She had som ice hanging from the bowfender though, very realistic.
It was very funny and will try it again. It is on some rare occations when the ice is just the right thickness for our boats.
Here´s another video with that enginesound, in the very beginning you can hear the "engine" barely ticking over.
http://www.youtube.com/watch?v=ot613BJiaY0All the best!
Hama