Yes, they are real.
Yes, submarines are real vessels designed for underwater operations. They are used by navies around the world for various purposes, including military defense, research, and exploration. Submarines can operate at great depths and are equipped with advanced technology for navigation, communication, and combat.
They are very real.
The marines do not use submarines. Only the Navy does.
german submarines
german submarines
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Submarines are used both for military and rersearch purposes.
military submarines use low frequency antenna that extends from the sail(conning tower.) The message is typed into a computer, then is sent to another submarines antenna that receives it and displays it on a computer.
the military and navy use it for war and combat. Many submarines are made for launching missels and taking down ships and other subs.
Civilian-Under water research. Military-Stealth
Francis C. Malko
The normal operating depth of submarines varies depending on their design and purpose. Most military submarines can operate effectively at depths of around 300 to 600 meters (1,000 to 2,000 feet), while some advanced models can dive deeper. Research submarines, like the DSV Alvin, can reach depths of over 4,000 meters (about 13,000 feet). However, the exact operational depth is often classified for military submarines.