SS Potaro was a refrigerated cargo steamship that was built in Belfast in 1904, and captured and scuttled in the First World War in 1915.

Potaro was the third of a trio of sister ships built for the Royal Mail Steam Packet Company (RMSP) in 1904.

[11] Her propulsion was by a single screw, driven by a Harland & Wolff three-cylinder triple expansion engine.

They took emigrants to South America from Spain and Portugal, and particularly from the Spanish ports of Vigo, A Coruña, Bilbao and Santander.

[16] On 10 January 1915 the German merchant raider SMS Kronprinz Wilhelm captured Potaro in the South Atlantic.

[9][17] On 10 September 1917 one of Potaro's sister ships, Parana, suffered engine trouble and fell behind from a convoy.

A German U-boat attacked her, but Parana returned fire with her defensive armament: a single naval gun on her poop.

In 1918 RMSP extended the usual route of the two ships southward from the River Plate to Patagonia, where they loaded meat at Río Gallegos and Puerto San Julián in southern Argentina and at Río Seco, Bahía San Gregorio and Punta Arenas in southern Chile.