EN
Using a laser transmitter in the range of 200 nm to 1200 nm, transmittance and total extinction coefficients were determined for two different but close related optical media which are ocean water and shallow well water in Mombasa County, in Kenya. The results were interpreted using Lambert–Beer’s law as applied for very small ranges of concentrations. It was established that the total extinction coefficients for two forms of water showed linearity with values of total extinction coefficients found to be µt = 7.734 (g/ml)-1 mm-1 and µt = 127.6 mm-1 at a wavelength of 638 nm for ocean water and shallow well water respectively.