Niger was almost a museum piece by 1914. She had been laid down at Naval Construction & Armament in Barrow on 17 September 1891, launched on 17 December 1892, and commissioned on 25 April 1893 - the products of an age when the Royal Navy was still arming itself against the French and the Russians. In her first life she served as a training ship and tender. In 1902, at Palmers Shipbuilding on the Tyne, she received larger engines and Reed water-tube boilers and went back into service in the same supporting role. By 1909 her hull was obsolete enough as a gunboat that the Navy converted her to a minesweeper, the new and unglamorous trade that the spread of contact mines was making essential. She belonged to a squadron commanded by Geoffrey Spicer-Simson, an officer whose later war would be far stranger: in 1915 he would lead a tiny British flotilla overland and across Africa to defeat a German force on Lake Tanganyika.

Walther Forstmann would become one of the deadliest submarine commanders of the First World War, eventually credited with sinking nearly 150 Allied ships. In November 1914 he was at the start of that career, operating from Belgian ports that had only just fallen to the German advance. His U-boat - based at Zeebrugge or Ostend, much closer to British waters than any German harbor on the North Sea - reached the Downs anchorage off Deal in foul weather. Niger lay there at her cable. Around noon Forstmann fired. The torpedo hit, and black smoke rolled into the gale. Niger was the first ship Walther Forstmann ever sank. She was also the first Allied warship sunk by a U-boat operating from the new Belgian bases - the proof, only three months into the war, that the seizure of the Channel ports had given Germany a knife at England's throat that the Royal Navy had not entirely planned for.

There was no time and no kindness in the weather. The wind was high and the sea was running heavily; some of Niger's men had been at the mess table when the torpedo struck and reached the deck in shirtsleeves. Watchers on the Deal seafront saw the explosion, saw the smoke, and saw boats put out from the shore to row through the gale toward the dying ship. Lieutenant-Commander Arthur Thomas Muir, who had the bridge, stayed there until his crew was off; he was seriously hurt in the explosion. All Niger's officers were saved. Seventy-seven of her men came off alive. Four were wounded. The squadron commander, Geoffrey Spicer-Simson, was not aboard - he was at a nearby hotel visiting his wife and her friends when his ship was sunk, an absence that did not endear him to the Admiralty. He would be transferred. Africa was waiting.

The date carries a weight now that it could not have carried then. On 11 November 1914 the war was three months old. The Western Front had locked into trench lines that would not move for four years. Britain had not yet learned what U-boats would do to her merchant shipping; the convoy system was years away; the great submarine campaigns of 1917 lay invisible in the future. The Niger went down on a date that, on a different November in 1918, would become the moment the guns stopped. Her wreck still lies on the seabed off Deal, two miles out from where holidaymakers walk on the pier. She is one of the earliest Royal Navy losses of a war that would, by its end, sink more than a thousand of Britain's ships - and force the navy that lost her to invent the techniques that won the next round.