A subsurface acoustic reflection study has been carried out in the Gulf of Paria with an Edo UQN Echo-sounder and a Precision Graphic Recorder of The Alden Electronics and Impulse Recording Equipment Co., Inc. Using a very short ping length for maximum resolution, penetration below the bottom in excess of 0.03 sec (45 m) was commonly obtained in water depths up to 100 m....
van Andel, Tjeerd H., and Peter L. Sachs. 1964. "Sedimentation in the Gulf of Paria during the Holocene transgression; a subsurface acoustic reflection study." Journal of Marine Research 22, (1). https://elischolar.library.yale.edu/journal_of_marine_research/1017