HMS Otus (S18) was a Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 Oberon-class

Oberon class submarine

The Oberon class was a 27-boat class of British-built diesel-electric submarines based on the successful British Porpoise-class submarine....

 submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

. Built in 1962 at Scotts Yard in Greenock

Greenock

Greenock is a town and administrative centre in the Inverclyde council area in United Kingdom, and a former burgh within the historic county of Renfrewshire, located in the west central Lowlands of Scotland...

, Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, the sub's trials were conducted in Scottish waters, mainly Loch Long

Loch Long

Loch Long is a body of water in Argyll and Bute, Scotland. The sea loch extends from the Firth of Clyde at its southwestern end. It measures approximately 20 miles in length, with a width of between one and two miles...

 and Loch Fyne

Loch Fyne

Loch Fyne is a sea loch on the west coast of Argyll and Bute, Scotland. It extends inland from the Sound of Bute, making it the longest of the sea lochs...

. Her pennant number (S18) was carried in white paint on the ship's conning tower

Conning tower

A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....

 fin, however this was removed in 1964 as a discontinued practice.

The first commission of HMS Otus included large-scale missile trial exercises in the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 and visits to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and Halifax

City of Halifax

Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

In July 1987, a team of British, Commonwealth and International submariners took part in trials in Bjornafjorden, nr Bergen, Norway, aboard Otus. They ran a series of progressively deeper escapes, starting at 30 metres (98.4 ft). At 90 metres (295.3 ft), individuals started to drop out. At the end of the trials two submariners reached a depth of 183 metres (600.4 ft). This set a new world record which to date has not been broken. Of the two record breakers, the first (commander of the Submarine Escape Training Tower

Submarine Escape Training Tower

A Submarine Escape Training Tower is part of a facility used for training submariners in methods of emergency escape from a disabled submarine. It is a tall cylinder filled with water with several entrances at varying depths each simulating an airlock in a submarine...

 at HMS Dolphin)) was a regular ascent under control. The second, a Petty Officer Instructor from SETT suffered a emergency release having given the alarm signal whilst flooding up the chamber. It was considered safer and quicker to escape him rather than depressurise and drain down. Both escapee suffered no lasting effects and returned to normal service. Both received military honours of the British Empire in the following years for this act.

HMS Otus was decommissioned in the early 1990s and resided at Pound's scrapyard in Portsmouth for several years. http://virtualglobetrotting.com/map/16174/ She was later purchased by a German entrepreneur, who moored her in the harbour of the town of Sassnitz

Sassnitz

Sassnitz is a town on the Jasmund peninsula, Rügen Island, in the Federal State of Mecklenburg-Vorpommern, Germany. The population as of 2007 was 10,747....

 on the island of Rügen

Rügen

Rügen is Germany's largest island. Located in the Baltic Sea, it is part of the Vorpommern-Rügen district of Mecklenburg-Vorpommern.- Geography :Rügen is located off the north-eastern coast of Germany in the Baltic Sea...

 in Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

to act as a floating naval museum.http://www.hms-otus.com/englishpage/indexenglish.php