Converted from the cross-Channel packet ship SS Riviera, she was initially fitted with temporary hangars for three seaplanes for aerial reconnaissance and bombing missions in the North Sea.

Riviera and her aircraft then spent several years spotting for British warships bombarding the Belgian coast and making unsuccessful attacks on targets in Germany.

The ship's six Babcock & Wilcox boilers generated enough steam to produce 11,000 shaft horsepower (8,200 kW) from the turbines,[2] enough for a designed speed of 20.5 knots (38.0 km/h; 23.6 mph).

[3] Riviera carried 400 tonnes (390 long tons) of coal,[2] enough to give her a range of 1,250 nautical miles (2,320 km; 1,440 mi) at 15 knots (28 km/h; 17 mph).

[4] Riviera was laid down by William Denny and Brothers at their Dumbarton, Scotland shipyard as a fast packet for the South East and Chatham Railway's Dover and Folkestone to Boulogne runs.

[4] Upon completion of the conversion, she rejoined the Harwich Force; in early May she conducted the handling trials of the prototype Short Type 184 floatplane.

[12] Riviera later saw service with the Dover Patrol where her aircraft flew spotting missions for naval bombardments off the Belgian coast.

[14] On 31 May 1919 the ship was sold back to her original owners, the South Eastern and Chatham Railway, and resumed her former role as a cross-Channel ferry.