Have you ever noticed that submarines are painted exactly black? In the first approximation, it becomes clear that black somehow does not correlate very well with the color of the water. Why aren’t submarines painted blue, cyan or grey?
No less interesting is the question of what kind of mysterious black rectangles are attached to the hull of a submarine. It all looks strange, but there are rational explanations for both questions.
Submarines in black
Submarines are painted black, not at all because they are “sweet and cool”. In order to better understand the issue, you should first look at marine life.
Their appearance was determined by evolution, which has adapted living organisms to an aggressive environment for millions of years. For example, sharks and whales have a light belly and a dark back. All in order to reflect less light penetrating from the surface. The situation is similar to submarines.
It would seem that water is much more associated with blue, dark blue, blue, even gray, but not black. Actually, it is not. You only need to look at photos of submarines on the surface to understand how black is much better at camouflaging a submarine, especially given its low profile relative to the surface of the water.
Note: Of course, there are exceptions. For example, in Iran, Israel, North Korea and a number of other coastal countries, submarines painted green are widely used. This is also done for masking, taking into account the shade of local coastal waters.
Most importantly, black reflects the least light, which increases the stealth of the submarine, not only on the surface but also underwater. The deeper the submarine sinks, the darker the water mass becomes.
Black color allows you to protect the eyeliner from visual detection when it goes at a very shallow depth. However, most submarines today are black, not so much because of the choice of paint, but because of the use of anechoic plates.
Show me your cubes
Now, as for the mysterious squares on submarines. These are the anechoic plates already mentioned above, which are attached to the submarine for the purpose of camouflage. But if the black color hides the submarine from visual detection, then the plates are needed to hide it from radar and noise detection. In simple terms, anechoic plates significantly increase the sound insulation of the ship’s hull. By the way, they are installed not only on submarines, but also on ships.
For the first time, anechoic plates were used by the Germans during the Second World War. In Germany, they were called “Alberich” after an invisible dwarf from Germanic mythology. However, after the end of the war, technology was forgotten for almost two decades. It was only in the 1970s that sound insulation returned to widespread use. Records of a modern type are made from multilayer synthetic materials.