A storm at sea is a serious matter: for coastal areas and especially for those who are on the high seas and have no way to return. Seafarers are specially trained on how to operate a ship in extreme weather conditions. This also applies to submarines, because, although they seem to be more protected than ships, they still cannot be on the surface during a storm.
The fact is that the waves on the sea move not only upwards, but spread in a circulatory way and in-depth. To understand how much, you need to know the height of the waves from above. The scale for its calculation was developed back in 1805 by the Irish hydrographer Francis Beaufort.
Its essence is in assessing the wind speed by its effect on, in particular, waves on the high seas. So, since 1874, the height of the waves has been officially estimated at 0-12 Beaufort points, where 0 points is calm, 5 points is medium-sized waves with an average height of 2 m, wind speed is 8-10 m/s
10 points is already a strong storm, wind speed 24-28 m/s, waves up to 12 meters high, which cause destruction of coastal structures and uproot trees
12 points is a hurricane, wind speed from 33 m/s, waves over 15 m, and extremely destructive, however, such cases are recorded at sea extremely rarely. Although the scale was expanded from 12 to 17 points for tropical hurricane winds (usually in China and Taiwan)
So, in order to know at what depth it is safe to lower the submarine, its captain calculates the wavelength: at 10 Beaufort points, the average wavelength is 210 m, and the depth is half as much, which means 105 m
By the way, quite a few submarines did suffer from storms, especially diesel-electric submarines in the first half of the 20th century, which, due to the limited battery capacity, simply could not be at great depths for a long time. However, sometimes this happened with nuclear submarines.
Moreover, according to scientists, there are internal waves in the ocean depths. They are dangerous for submarines because they can push them to a great depth with a dangerous level of pressure.
