HMS Amethyst (U16) was a Modified Black Swan-class sloop of the Royal Navy. She was laid down by A. Stephen & Sons Ltd of Glasgow, Scotland on 25 March 1942, launched on 7 May 1943 and commissioned on 2 November 1943.

In World War II she served as a convoy escort in the North Atlantic. On 20 February 1945 she depth charged and sank U-1276 south of Waterford, Ireland.

The Amethyst incident

In 1949 Amethyst was involved in the Chinese Civil War. The events are known as the Amethyst incident and as the Yangtze incident.

During the Chinese Civil War, the United Kingdom kept a warship on the Yangtze River at Nanjing, ready to evacuate the British Embassy staff and other UK citizens. On April 19, 1949 Amethyst was dispatched to take over from Consort . At this time the People's Liberation Army (PLA) of the Communist Party of China controlled the north bank of the river while the Kuomintang controlled the south bank. A truce was being observed, but was due to expire on April 20.

At 08:30 on April 20 Amethyst was attacked by artillery of the PLA. At about 09:30 as the sloop approached Kiangyin a shell hit the wheelhouse and the injured coxswain grounded Amethyst on Rose Island. Another shell mortally wounded Lieutenant Commander B. M. Skinner. By the time the shelling stopped at about 11:00, 22 men had been killed and 31 wounded. About 65 men were ordered to abandon ship and attempt to escape to Kuomingtang controlled territory. Some were shot in the water, but the survivors made it back to Shanghai.

Consort arrived to tow Amethyst off the island, but came under heavy fire, and abandoned the attempt with 10 killed and 3 injured. On April 21 another attempt was made to rescue Amethyst, this time by the cruiser London and the sloop Black Swan but they too were heavily shelled and retreated with 3 killed and 14 wounded. More than 250 PLA soldiers were killed in these artillery duels.

Lieutenant Geoffrey Weston refloated Amethyst on April 22 and moved her out of range of the PLA's artillery. Lieutenant-Commander John Simon Kerans joined the ship later that day and assumed command.

Amethyst remained under guard by the PLA for ten weeks. Negotiations were stuck because Kerans would not accept Major Kung's demand that the British admit to having opened fire first.

On July 30 1949 Amethyst slipped her chain and headed downriver in the dark. She followed the merchant ship Kiang Ling Liberation, which showed the way through the shoals and distracted the PLA. She ran the batteries at Kiangyin and Woosung, and met Consort at 05:30 on July 31.

Amethyst re-enacted her role in the 1957 film Yangtse Incident: The Story of HMS Amethyst (released as Battle Hell in the USA, and also as Escape of the Amethyst and Their Greatest Glory) starring Richard Todd as Kerans.

See HMS Amethyst for other ships of this name.