Launched in 1908, the Salsette was an express mail liner owned by the P&O line. On her fated final voyage, she carried 31 passengers and 20 tons of general cargo from London to Bombay. She was once described as one of the most beautiful straight-stemmed steamers ever built. There were 600 brass portholes on her white hull; with her yellow funnels, she looked more like a luxury yacht than a liner. At 440ft long, with a beam of 53ft and 10,000hp engines driving her twin screws, her top speed was 20 knots. On her maiden voyage, she broke the Marseilles — Bombay record, and later went on to break other records. At one point she even held the Blue Ribband for the fastest transatlantic crossing.

On 20 July 1917, as she approached the east side of Portland Bill, she was spoken to on semaphore by torpedo boat 85 who instructed her to keep 4 miles south of the Bill due to mine laying operations. She complied, and having cleared the Bill, she turned NW into Lyme Bay bringing her speed up to 16.4 knots. With calm conditions in Lyme Bay, the liner was following a standard zigzag pattern.

Oberleutant Howaldt, on UB-40, had spotted her and positioned himself so that the ship would pass close by ( He had sunk a total of 63 ships) . The plan worked. One torpedo was fired, which was spotted in-bound by Mate Arthur Vaughn who shouted hard to starboard. But it was too late. The torpedo struck the liner amidships on the starboard side killing 15 crewmembers. It destroyed everything in its path including a number of lifeboats. An immediate order to abandon ship was given, and 15 minutes after being hit, the majestic liner listed to port and slipped under the waves.

Today the wreck stands 15m of the 45m seabed on her port side.