Method and apparatus for improving the shallow water performance of a depth sounder

摘要

Acoustic delay means are interposed between the face of a transducer and the bottom of a vessel, with the delay being equal to or greater than the shallowest depth the associated depth sounder capable of, whereby subtracting out the depth associated with the acoustic delay, the water under the vessel can be measured down to zero feet. In a preferred embodiment, a water column is utilized as the delay media, with the transducer being mounted at the top of the water column and with the water column being terminated at the bottom of the boat. The transducer pulses are projected through the water/hull/water interface to the water beneath the vessel. For digital depth sounders, the depth associated with the water column may be subtracted out to give the zero reading.