 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.On 4 July, "Riviera" and "Engadine" attempted to launch aircraft to reconnoitre the River Ems and lure out a Zeppelin so that it could be attacked.Only one of "Riviera"s two Short Brothers floatplanes was able to take off successfully and it dropped a few small bombs without noticeable effect.