Underwater warfare is one of the three operational areas of naval warfare, the others being surface warfare and aerial warfare. It refers to combat conducted underwater such as:

• Actions by submarines actions, and anti-submarine warfare, i.e. warfare between submarines, other submarines and surface ships; combat airplanes and helicopters may also be engaged when launching special dive-bombs and torpedo-missiles against submarines;
• Underwater special operations, considering:
  • Military diving sabotage against ships and ports.
  • Anti-frogman techniques.
  • Reconnaissance tasks.