Psilo

I've been told an electromagnetic submarine was made in the 1970's by a Professor and his students from a California university. There were no moving parts and the sub moved slowly. I've done some searching and I haven't been able to find anything. Any information would be appreciated.

I have a vague understanding of simple electric motors. Something I don't understand is how the commutator reverses the polarities. It'd be great if someone could help me out.