Have you ever seen one like this?
You put soda or beer in the little hole in the top. Then it
is supposed to propell it across the water.
Yes I have. Didn't have a bathtub to play with it (ain't much room in a washtub) but it didn't work in the 50's and I doubt it'll work now. lol
Bought a couple of wooden ones a couple of years ago (Chinese) and I think you mixed baking soda and water for the bubbles.