There is no "usable" light agter 200 meters...
200m
Sunlight can penetrate into the ocean to an average depth of about 200 meters (656 feet). This depth can vary depending on factors such as water clarity, time of day, and geographic location. Beyond this depth, the ocean becomes progressively darker as less sunlight is able to penetrate.
The upper 100 -200 m of the ocean is called the Photic zone (photo = light).At about 150 meters 99% of light is absorbed.Beyond the Photic zone, light does not penetrate, and it is pitch dark.
blue
The average depth of the Indian ocean is I dont know honestly
sound waves can penetrate the ocean floor.
the average depth is 3456m
they are absorbed
the more you go down the denser the water gets until the water is so dense that the sunlight can't reach the bottom of the ocean.
The average depth of the world ocean is approximately 12,080 feet (3,682 meters). This value includes both shallow coastal areas and deep ocean trenches, giving an overall average depth for the entire ocean.
The Pacific
Red
jolly AVERAGE DEPTH: PACIFIC OCEAN:4300 M ATLANTIC OCEAN:3600 M INDIAN OCEAN:3500 M