PS Portsdown was a passenger vessel built for the Southern Railway in 1928.

[1] She was one of the civilian ships that participated in the Dunkirk evacuation in 1940 and was sunk by a naval mine a year later.

[2] Portsdown was retained on the Portsmouth to Ryde run during the Second World War along with her sister ship Merstone.

However, on 1 June 1940, she was employed as a naval transport ship and went unarmed to Dunkirk, where she used her own boats to load men from the beach, later putting her bow into the shore to rescue others.

[3] Portsdown hit a mine on 20 September 1941 at Spithead and sank with the loss of 23 lives[4]