In 1920, she was sold to the Brazilian Navy serving under the name Alexandrino de Alencar and was renamed Maranhão in 1927.

Maranhão remained in service when Brazil entered the Second World War, being used for patrol and convoy duties.

The ship was fitted with a 2-pounder "pom-pom" anti-aircraft autocannon during the First World War, while in 1918 the torpedo tubes (and possibly one of the 4-inch guns) was removed to allow a heavy depth charge armament to be carried.

[15][16] On 23 December 1915, Porpoise and the destroyer Morning Star were escorting a Russian icebreaker when forced to hove to near Fair Isle in a heavy gale.

[17] She was under refit on 24 April 1916, and so did not take part in the Grand Fleet's sortie in response to the German Bombardment of Yarmouth and Lowestoft.

The flotilla leader Tipperary was badly damaged by German shells (mainly from the battleship Westfalen) and later sank, while the leading ships in the British formation fired a total of nine torpedoes, none of which hit.

Broke was badly damaged by fire from the cruiser Rostock and Westfalen, and collided with the destroyer Sparrowhawk, which was also rammed by Contest and was later scuttled.

After restoring steering, Porpoise limped away with two of her four boilers disabled by loss of feedwater, finally reaching the River Tyne in the company of Contest and Garland on 2 June.

[27] In order to counter German minelayers and to protect British minesweepers in the North Sea, the 4th Flotilla transferred to the Humber in July 1916.

[32][33] In September 1916, Porpoise was one of four destroyers of the 4th Flotilla that were ordered to the English Channel as a result of a spurt of U-boat activity.

[35][36] On the night of 25/26 February 1917, German torpedo boats attempted another raid against the Dover Barrage and Allied shipping in the Dover Straits, with one flotilla attacking the Barrage and a half flotilla of torpedo boats operating off the Kent coast.

Porpoise then arrived on the scene and drove UB-39 away, but although La Tour d'Auvergne was towed to Mullion, Cornwall, she was declared a constructive total loss.

[43][44] In March 1920, Porpoise was sold to Thornycroft for refurbishing and onwards sale to Brazil as Alexandrino Dealanca,[c] commissioning in the Brazilian Navy on 9 December 1922.

[49] During the war, she was fitted with sonar and depth charge rails, and her armament was supplemented by three Oerlikon 20 mm cannon.