Ducted empellors are indeed called a caterpillar drive. In the novel "Hunt for Red October" that is what the Russian sub used (as now used by the Royal Navy Trafalgar-class, the US Navy Seawolf-class, and the French Navy Le Triomphant class) The drive system "used" in the movie version was Magnetohydrodynamic drive or MHD propulsors.
From Wikipedia, here's a boat that used such a drive:
Yamato 1, is a boat built in the early 1990s by Mitsubishi. It uses a magnetohydrodynamic drive, driven by a liquid helium-cooled superconductor, and can travel at 15 km/h (8 knots).
The Yamato 1 was the first working prototype of its kind. It was completed in Japan in 1991, by the Ship & Ocean Foundation (later known as the Ocean Policy Research Foundation). The ship was first successfully propelled in Kobe harbor in June 1992. Yamato 1 is propelled by two MHD thrusters that run without any moving parts.
MHD works by applying a magnetic field to an electrically conducting fluid. The electrically conducting fluid used in the MHD thruster of the Yamato 1 is seawater.
In the 1990s, Mitsubishi built several prototypes of ships propelled by an MHD system. These ships were only able to reach speeds of 15 km/h, despite higher projections.
The Yamato 1 on display in Kobe, Japan
A MHD thruster from the boat, at the Ship Science Museum in Tokyo