The blue ocean
The ocean’s visible superficial waves are the product of the blowing winds pushing the sea waters on its surface. The deeper internal waves travel deep underneath the surface waters. These deeper internal waves result from the earth’s rotation and the difference in the density of the layers of water. The deeper ocean waters are colder, saltier, and denser. In contrast, the upper layers of waters are lighter and stream above the deeper inner ripples. The oceans have two different kinds of waves, the superficial ones and the deep ones, to put it differently. The phenomenon is narrated in the Quran as “waves above the waves.”
Deep waves are invisible
The internal waves are marked on the sea surface by bands of smooth and rough water. Someone standing on the seashore typically will not see the deep internal waves, which can be huge with heights of up to 100 meters and widths of hundreds of miles but nearly invisible.
Although these deeply hidden ripples are a recent scientific discovery, the Quran describes these deep wavy waters in the ocean, which are not visible to the ordinary observer.
(Quran 24:40) “….Or (the unbelievers’ state) is like the darkness in a deep sea. It is covered by waves, above which are waves, above which are clouds. Depth of darkness, one above another, if a man stretches out his hands, he can hardly see it!….”
Depths of darkness
When light travels through the ocean water, it gets progressively faint. Firstly, there is enough light to support photosynthesis and plants in the Photic zone, which is the top 200 meters of the ocean. Then comes the Aphotic zone at a depth of 200 to 1000 meters, where there is very little sunlight. Even with modern scuba diving equipment, the deep-diving record is 300 meters. If the depth is more than 1000 meters, sunlight cannot penetrate, and it is entirely dark. The ocean depth can vary greatly. Mariana Trench in the Western Pacific Ocean is the deepest point of all the oceans, about 11,000 meters or approximately 7 miles deep. Deep seas are undoubtedly a dark world, where “….if a man stretches out his hands, he can hardly see it!….” (the Quran 24:40).
To learn more about the significance of Qurans’ consistency with modern science, please read this: https://qpeace.net/?p=8207