Titanium’s remarkable strength, corrosion resistance, and light weight make it theoretically ideal for submarine construction ...

Such a battle group's speed ... Vessels like these and the Alfa-class belong to a subdivision called fast-attack submarines, which specialize in covert and shock operations such as insertion ...

Vessels like these and the Alfa-class belong to a subdivision ... covert surveillance of enemy battle groups, and ambush warfare. Speed, however, isn't a submarine's primary means of defense.