The North Koreans and Iranians are using very small submarines, similar to the ones under discussion here, probably for similar roles (covert infiltration of pe

The North Koreans and Iranians are using very small submarines, similar to the ones under discussion here, probably for similar roles (covert infiltration of people and goods). And similarly, operational security is probably the most important part of their mission as well. The US fills the same need with the Shallow Water Combat Submersible, delivered close to the target by another submarine in a Dry Deck Shelter. But that's because the US Navy has focused on long range operations.