She was powered by two 4-cylinder triple-expansion steam engines, each driving one shaft, which produced a total of 10,000 indicated horsepower (7,500 kW) designed to give a maximum speed of 23 knots (43 km/h; 26 mph).

[8] In April 1904 she took part in the Somaliland Campaign, including supplying men for the landing party that stormed and captured the forts at Illig, the ship's guns supporting the attack.

[8] Shortly before the beginning of the war, Rear-Admiral Herbert King-Hall, commander of the Cape Station, was ordered to find and shadow SMS Königsberg, based at Dar-es-Salaam, German East Africa.

Hyacinth hoisted his flag after Minotaur was ordered home as a result of the decisive victory over the German squadron in the Battle of the Falklands in early December 1914.

When the predreadnought battleship Goliath arrived later that month, he transferred his flag to her and ordered Hyacinth north to German East Africa.

[11] On 14 April Hyacinth intercepted the captured British merchantman SS Rubens making an attempt to deliver supplies to German East Africa.

[12] Rubens was scuttled in shallow water in Manza Bay, out of sight of Hyacinth, which believed that shelling had set her afire, though this was a ruse by the crew, who had laid inflammable material on deck and retired to the shore.

On 6 January, Squadron Leader Edwin Moon was on a reconnaissance flight with Commander Richard Bridgeman as observer, when they were forced to land with engine trouble and came down in a creek of the Rufiji River delta.

Moon and Bridgeman wandered for days in the river delta before eventually building a makeshift raft which was swept out to sea.

[15] Bridgeman's body was recovered from the sea and is buried in Dar es Salaam Commonwealth War Graves Commission Cemetery.