Abstract

Method and apparatus for detecting the presence of hydrocarbons and other substance that fluoresces or absorbs light within a body of water which utilizes a controlled submersible vehicle scanning at or near the water bottom. The method utilizes a selected frequency light source as carried by the submersible to scan the water bottom, and the returned light energy, either at the wavelength of oil fluorescing in water or the source frequency backscatter, is detected and processed for the water bottom as well as a water region that is a selected distance above the water floor. Alternative forms of apparatus are disclosed for carrying out the functions of both oil fluorescence detection, and for obtaining differential absorption readings as to light source backscatter energy that is created by the ambient water and other factors in the water environment such as marine life, turbidity, etc.