5842-ton P&O express mail liner, built Greenock, 1908. 440ft x 53ft. 10,000hp quadruple-expansion engines.

Cargo: 31 passengers and 20 tons general, London for Marseilles and Bombay. Position: 50 29.67N 2 43.07W.

Depth: 43m.

Sunk: 20 July, 1917 by torpedo in the starboard side of engine room from UB-40 (Oberleutnant Howaldt). 15 crew killed.

Diving: Fantastic. Complete ship lying on port side. Splendid finds amid luxury fittings of interior. Least depth of 32m (to starboard rails). See Wreck Tour.

Launch: Lyme Regis; Weymouth.

She was beautiful and she was fast. Yet she rolled a lot and at her top speed shipped a lot of water. Despite this, passengers to India vied to get a cabin aboard the liner Salsette, which had been built for the P&O by Caird in Greenock in 1908.

She was described as one of the most beautiful straight-stemmed steamers ever built and, with 600 portholes in her white hull and her yellow funnels, she looked more like a billionaires yacht than a passenger liner.

The 5842-ton Salsette was 440ft long with a beam of 53ft, and her 10,000hp quadruple-expansion engines and twin bronze screws could drive her along at 20 knots. On her maiden voyage, she broke the Marseilles-to-Bombay record and later beat the Bombay-to-Aden record by a wide margin.

When war came, it was her speed that appealed to everyone. The fastest a U-boat could manage was 13.5 knots on the surface and only 7 knots submerged. The Salsette could leave any submarine standing and, according to gossip, the German Navys High Command had put a price on her head, with instant promotion to go to the U-boat crew that could torpedo her.

Whether or not that was true, it is certain that so high was the Salsettes speed that the 4.7in gun mounted at her stern was never used to fire a shot in anger.

The speed of the Salsette - which was named after a small island off Bombay - kept her safe until plain bad luck and a zigzag course, following Admiralty instructions, took her close across the open mouths of UB-40s bow torpedo tubes at one minute after noon on 20 July, 1917. Captain Howaldt fired once from periscope depth.

It was flat calm in Lyme Bay, but no one on board the liner saw UB-40, nor her periscope. Finally, it was the Mate, Arthur Vaughn, on the monkey-bridge, who spotted the tell-tale white-feather line of the torpedo streaking towards them.

He shouted Hard a-starboard, but it was too late. The torpedo struck amidships on the starboard side near the stokehold, killing 15 men there and in the engine room. A great column of water rose in the air, taking several lifeboats with it and hurling spars 15m above the head of Captain Albert Armitage, RNR, on the bridge.

The captain said later that, despite the fact that all her watertight doors were shut and her main deck scuttles fitted with deadlights screwed down, he knew at once that the Salsette was done for. She became dead and it felt as though she was collapsing like a pack of cards.

Moments later, he gave the order to abandon ship - an evacuation which was completed in five minutes. Forty-five minutes later, the Salsette listed to port and sank.

Howaldt took UB-40 down and sat out several depth-charge attacks before surfacing and sinking another steamer, the British collier L H Carl, just one hour after the Salsette.

Rumours that the Salsette was carrying a vast sum in money to pay troops in Egypt spread soon after the end of the war. Officially, she was carrying 20 tons of cargo for people in Marseilles and Bombay, together with 23 bags of confidential mail for the senior naval officer in Gibraltar, the Army in Egypt and the Viceroy in Bombay.