Any fan of the film The Hunt for Red October will remember a discussion about the ‘Caterpillar Drive’ or Magneto Hydrodynamic Drive (MHD).  It’s sort of a jet engine for the water which electrifies the water (creating ions) and pushes them along using magnets.

You can build a simple MHD using nothing more than a battery, some wire, warm water, salt and pepper.  Here is a video of one I built.

SAFETY:  The bubbles coming off the water are hydrogen and oxygen gas.  Use in a well ventilated area, away from sparks.

Here is another one: