How does a submarine surface?
There are several ways to get to the surface, including blowing to the surface and driving to the surface. Blowing to the surface can be done at any depth by blowing high-pressure air into the ballast tanks. As the air replaces the seawater in the ballast tanks, the submarine becomes lighter, causing it to rise to the surface. To drive to the surface, the submarine simply positions its planes (i.e., stubby "wings" at the stern and on the superstructure or bow of the submarine) to rise and the submarine ascends to the surface. The submarine then uses low-pressure air to force seawater out of its very large ballast tanks to remain on the surface.
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