The distance that light can travel through water depends on several factors, including the clarity of the water, the presence of impurities or particles, and the wavelength of the light.
In clear ocean water with minimal impurities, light can penetrate to significant depths. Sunlight can typically reach depths of around 200 meters (656 feet) in the open ocean, although the intensity of the light decreases exponentially with depth. This is why the colors of light become progressively dimmer and bluer as you descend deeper into the ocean.
However, in more turbid or cloudy water, or in areas with high concentrations of particles, the penetration depth of light decreases significantly. Suspended particles and impurities in the water scatter and absorb light, reducing its ability to travel long distances. In such conditions, light penetration might be limited to just a few meters or less.
The wavelength of the light also plays a role. Blue light tends to penetrate water more effectively than other colors because water absorbs longer-wavelength light (e.g., red) more readily. This is why the underwater environment appears predominantly blue or green, as the shorter wavelength blue and green light can travel deeper.
Overall, the distance light can travel underwater varies based on water clarity, impurities, and light wavelength, but it generally ranges from a few meters to hundreds of meters in clear ocean water.