Fernlenkboot!
The remote-controlled ''FL-boat' was the
Kaiserliche Marine's ambitious project produced by
Siemens-Schuckertwerke to sink British Royal Navy monitors operating off the Flanders coast. "
They were driven by internal combustion engines and controlled remotely from a shore station through spooled wire unwound behind the boat. The wire was 20 kilometres (12 mi) long and the spool weighed 800 kilograms (1,800 lb). An aircraft could be used to signal directions to the shore station by radio." (via wikipedia)
This article the 'New Hun Device' likely pertains to one such attack on HMS Erebus (second image below), which occurred two weeks prior on 28 October. That ship was damaged but not sunk. Might anyone know what type of airplane was used for spotting during this incident?
(from the Malaya Tribune, 13 November 1917):



(iage via wikipedia)