You and the Piranha sank all but two of their operational submarines.

The ten-torpedo salvo was the largest ever fitted to an operational submarine.

She was designed to look after nine operational submarines, supplying over 100 torpedoes and a similar number of mines.

But I'm sure you see, it's such a close confinement in an operational nuclear submarine, working underwater.

There was no other submarine operational within a thousand miles.

In all, evidence indicates that a combined total of over twenty operational submarines were built by both sides during the conflict.

By 1989, there were over 400 nuclear-powered submarines operational or being built.

At the end of the Cold War in 1989, there were over 400 nuclear-powered submarines operational or being built.

There were 77 operational submarines at the beginning of the war, with 15 under construction.

Germany has 38 operational submarines to begin the year.