Anchor drift indicator

For use with an ocean going vessel having a main anchor, an anchor drift indicator comprising:

• a first buoy having an exterior wall;
• a first tether line attaching said first buoy to the vessel main anchor;
• a first light disposed on said first buoy;
• a first electrical supply means for supplying electricity to said first light;
• a first magnetically actuated switch controlling said first light, said first switch located within said first buoy sufficiently close to the exterior wall of said first buoy so as to be operable from outside the exterior wall of said first buoy, whereby no portion of said first switch extends beyond the exterior wall of said first buoy and thus said first switch is not exposed to a marine environment;
• a reference buoy having an exterior wall;
• a second anchor for positive securement to an ocean bottom near the main anchor;
• a second tether line attaching said reference buoy to said second anchor;
• a second light disposed on said reference buoy;
• a second electrical supply means for supplying electricity to said second light;
• a second magnetically actuated switch controlling said second light, said second switch located within said reference buoy sufficiently close to the exterior wall of said reference buoy so as to be operable from outside the exterior wall of said reference buoy, whereby no portion of said second switch extends beyond the exterior wall of said reference buoy and thus said second switch is not exposed to a marine environment,
• whereby upon failure of the main anchor to firmly engage the ocean bottom, the main anchor will drag along the ocean bottom causing said first buoy to change position, this change in position being clearly visible from the vessel as a divergence between said first buoy and said reference buoy which remains stationary, this change in position indicating anchor drift.

An anchor drift indicator comprising:

• a first, floating buoy attachable to the main anchor of an ocean going vessel by a first tether line, wherein said first buoy is tethered to the main anchor and floats on the ocean surface, said first buoy including a radio transmitter means for sending a signal to the vessel and a radio receiver means operating to inhibit said transmitter upon receipt of an inhibiting signal;
• a floating reference buoy attached to a second anchor by a second tether line, said reference buoy being deployed in close proximity to said first buoy, said reference buoy being secured by said second anchor to a location on the ocean bottom, said reference buoy also floating on the ocean surface in close proximity to said first buoy, said reference buoy including a second radio transmitter means operable to send a weak inhibiting signal, receivable by said first buoy radio receiver means;
• and
• alarm means on the oceangoing vessel, and a second radio receiver means operable for actuating said alarm means upon separation beyond a predetermined proximity of said first buoy and said reference buoy, a weak inhibiting signal from said second radio transmitter means not being received by said first buoy radio receiver means whereupon said first buoy radio transmitter means sends a signal to said vessel radio receiver means, thus actuating said alarm means to indicate a condition of anchor drift.