Problems encountered in the development of an electromagnetic recording current meter for use in shallow water

The development and evaluation of a self aligning electromagnetic current meter with unique hydrodynamic characteristics is described. The specific testing of certain components such as the Fluxgate compass and electromagnetic current sensor is also reported along with comments on the suitability of the device for use on slack coastal zone moorings based on test results. The ocean current meters tested have been designed to enhance their hydrodynamic properties. This has resulted in an underwater instrument housing in the shape of a prolate spheroid (torpedo-shape) with appropriate vertical and horizontal stabilizing fins. To complement the hydrodynamic design, the ocean current meters tested were equipped with a new "unit electrode", an ocean current sensing technique employing electrodes that can be placed on the surface of almost any shape and which have individual magnetic fields associated with them.