Sounds like the underwater craft seen by the expedition of Admiral Byrd to the Antarctic. I have a goldmine of links in my favourites, which if removed can usually be found on the WBM. The video I had has been removed, and not saved on WBM, or so they say! I found another..

https://www.youtube.com/wa...

"The inventor of the Navy's most bizarre patent, the straight-out-of-science fiction-sounding hybrid aerospace/underwater craft, describes that craft as leveraging the same room temperature superconductor technology and high energy electromagnetic fields to enable its unbelievable speed and maneuverability."

https://web.archive.org/we...