Air Independent Propulsion (AIP) System

Air Independent Propulsion (AIP) is a technology that allows Diesel Submarines to operate without having to surface or use a snorkel to access atmospheric oxygen .Navies who wish to operate non-nuclear subs with long-range and large weapons payload are now option for large diesel submarines equipped with AIP, which provide the closest alternative to nuclear powered submarines.

Some examples are the Soryu class of Japan, Type 216 being developed by Germany and the Shortfin Barracuda of France which will be operated by Australia.