An underwater propulsion device is disclosed comprising two sleeves for fitting around each of a user's lower legs, with each sleeve mounting a propulsion unit, and the sleeves being connectable by a bar between them during underwater operation of the device by the user.

An underwater propulsion device is disclosed comprising two sleeves for fitting around each of a user's lower legs, with each sleeve mounting a propulsion unit, and the sleeves being connectable by a bar between them during underwater operation of the device by the user.

A magnetohydrodynamic propulsion device (MHD), having a superconducting magnet, a cryogenic refrigeration system adapted to cool the superconducting magnet, a vacuum cryostat surrounding the superconducting magnet, an electrode pair, and a housing adapted to mount the MHD to a vessel, wherein the superconducting magnet and the electrode pair are adapted to receive electrical power and generate a magnetic field, an electric field, and an electrode current density to produce thrust in an electrically conducting medium in contact with the MHD.

A magnetohydrodynamic propulsion device (MHD), having a superconducting magnet, a cryogenic refrigeration system adapted to cool the superconducting magnet, a vacuum cryostat surrounding the superconducting magnet, an electrode pair, and a housing adapted to mount the MHD to a vessel, wherein the superconducting magnet and the electrode pair are adapted to receive electrical power and generate a magnetic field, an electric field, and an electrode current density to produce thrust in an electrically conducting medium in contact with the MHD.