HMS Grampus (N56) was the lead ship of her class of mine-laying submarine of the Royal Navy.

She served in World War II off China before moving to the Mediterranean Sea.

She was seen by the Italian torpedo boat Circe, which was on anti-submarine patrol with Clio, Calliope, and Polluce.

Wreckage came to the surface along with air bubbles and oil.

This article about a specific naval submarine of the United Kingdom is a stub.