Recovery system for a submerged instrument

A recovery system for a submerged instrument comprising:

• a buoyant member;
• a buoyant member releasing mechanism comprising an electrically promoted magnetic flux diversion device comprising a pair of pole pieces, a permanent magnet disposed between said pole pieces, and a release plate comprising ferromagnetic material bridging one end of said pole pieces, said pole pieces and permanent magnet forming tow flux paths with said release plate forming a portion of one of said flux paths;
• guide means allowing axial separation of the release plate form the pole pieces while preventing lateral motion;
• control winding means associated with the pole pieces for receiving a pulse of electrical current and disposed for producing a momentary magnetic field opposite to that of the permanent magnet to divert the flux path from the path that includes the release plate to the other flux path;
• current supply means for supplying a pulse of electrical current to said control winding;
• a mooring device having a weight that exceeds the buoyant force of the buoyant member;
• means connecting said release plate to the mooring device;
• and
• a tether line connected between the release plate and the buoyant member to allow the buoyant member to rise relative to the mooring device upon release from the pole pieces.