HMS Grampus (S04) was a Porpoise-class submarine

British Porpoise class submarine

The Porpoise class was an eight-boat class of diesel-electric submarines operated by the Royal Navy. This class was originally designated patrol submarines, then attack. They were the first conventional British submarines to be built after the end of World War II...

. Her keel was laid down in 1955 by Cammell Laird

Cammell Laird

Cammell Laird, one of the most famous names in British shipbuilding during the nineteenth and twentieth centuries, came about following the merger of Laird, Son & Co. of Birkenhead and Johnson Cammell & Co. of Sheffield at the turn of the twentieth century.- Founding of the business :The Company...

 at Birkenhead

Birkenhead

Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...

. She was commissioned

Ship commissioning

Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...

 in 1958.

On 1 April 1963, Grampus returned to Gosport

Gosport

Gosport is a town, district and borough situated on the south coast of England, within the county of Hampshire. It has approximately 80,000 permanent residents with a further 5,000-10,000 during the summer months...

 after spending three weeks under the polar icecap looking for holes in the ice. During the patrol she superficially damaged her hull on the ice.

On 11 January 1968, the French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 trawler Fomalhaut caught Grampus in her nets in the English Channel

English Channel

The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

. Grampus surfaced and both crews spent over three hours disentangling the nets.

Grampus operated with USS Tigrone

USS Tigrone (SS-419)

USS Tigrone , a Tench-class submarine, was the only ship of the United States Navy to be named for the tigrone, a tiger shark found in tropical waters. Her keel was laid down on 8 May 1944 by the Portsmouth Navy Yard. She was launched on 20 July 1944 sponsored by Mrs. Charles F...

in a joint American-British oceanographic operation in the eastern Atlantic in 1972.