Dolphin (ex-hms Pandora).

The steel screw steamer was built as Seti by Sir Raylton Dixon at Middlesbrough in 1902 for the Moss Steamship Company. The Admiralty bought it in 1914 and named it Pandora. It was converted into a submarine depot and repair ship in 1920 to 1921, then renamed Dolphin in 1924. Decommissioned by 1939, it was being towed from Portsmouth to Blyth or nearby Cambois for stripping before planned use as a blockship at Scapa Flow.

On 23 December 1939 Dolphin struck a mine laid by the German submarine U-22 about three days earlier, roughly one and a half miles south-east of Blyth. Some records give 23 November, but the detailed loss account supports 23 December. The vessel sank while under tow, so it was not fighting when lost.

No deaths were recorded. Because the old ship was being towed for disposal rather than operating with its former naval complement, the loss did not repeat the large human disasters associated with some depot ships.

The wreck is about 100 metres long in roughly 18 to 19 metres of water, with a least depth reported near 11.8 metres. The bow is relatively recognisable, while much of the rest is heavily broken, salvaged and partly buried. The point is off Blyth in Northumberland, not in the Scottish Borders as the saved county description suggests.

Across three names, the ship served merchant trade, First World War naval support and inter-war submarine work. Its final loss came just before it could be sunk deliberately to protect Scapa Flow. That long change of use makes the wreck more important than its quiet final tow might suggest.