A pulsed heat energized system for detecting corrosion or similar oxidation products located intermediate a layer of metal and an overlying layer of paint or other metal protective material. A cable winding bobbin, having an internally toothed crown, is provided in the device’s body and a drive mechanism rotates the bobbin in the chosen direction to achieve predetermined angular positions. At the transmitter, a spreading and subcarrier mapping unit spreads an input data symbol with a complex quadratic sequence code to generate a plurality of chips and maps each chip to one of a plurality of subcarriers. As a result, contact holes are prevented from shorting with each other through a void, and thus current leakage is suppressed. Each vane member is selectively rotated to one of a lift or thrust position according to an arcuate location of the vane as it passes through the water. The recess is in fluid communication with the inlet channel.