The chart shows light transmission in the clearest of any seawater (Jerlov Type I Oceanic) and likely that seen off the west coast of the Big Island of Hawaii. Later in this thread I posted light transmission in the clearest of 'green' Coastal water (Jerlov Type I Coastal; probably that off the Florida coastal where nutrient loading from runoff, rivers and streams, septic tanks and water reclamation facilities occurs.)FWIW, here is a graph from one of Dana's articles showing the light spectrum at 10 feet deep in sea water. There's much more green, orange and red than there is in the spectrum from a typical light fixture.