HMS Thetis was an Apollo-class

Apollo class cruiser

The Apollo class were a class of second-class protected cruisers built for the Royal Navy in the late 19th century that served during the Boer War and World War I....

 2nd class protected cruiser

Protected cruiser

The protected cruiser is a type of naval cruiser of the late 19th century, so known because its armoured deck offered protection for vital machine spaces from shrapnel caused by exploding shells above...

 of the 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...

, launched

Ship naming and launching

The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...

 on 13 December 1890. Her first significant mission was service in the Bering Sea Patrol with American warships in a combined effort to suppress

Bering Sea Anti-Poaching Operations

Bering Sea Anti-Poaching Operations were conducted in 1891 by the navies of the United States and the United Kingdom. Due to the near extinction of the seal population in the Bering Sea, the American and British governments dispatched a squadron of warships to suppress poaching...

 poaching

Poaching

Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...

 in the Bering Sea

Bering Sea

The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....

. The latter half of her career was spent as a mine-layer. Laden with concrete she was deliberately sunk in attempt to block the canal in the Zeebrugge Raid

Zeebrugge Raid

The Zeebrugge Raid, which took place on 23 April 1918, was an attempt by the British Royal Navy to neutralize the key Belgian port of Bruges-Zeebrugge...

 during the First World War

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, on 23 April 1918.