Chapters: 0:00 How fast should a submarine move to remain stealthy? 1:27 How can a submarine be noisy when it's not moving? 2:33 The three categories of submarine noise explained 4:35 How much noisier a submarine becomes when it doubles its speed 6:00 Why cavitation bubbles are bad for a submarine 7:24 How propeller design impacts submarine stealth 9:31 How going deeper makes submarines more quiet 10:53 Why a fast-moving submarine can't be aware of its surroundings 11:47 Why submarines rarely use their active sonar

Source: Why Submarines STOPPED Firing Torpedoes From The Nose