The German Focke company made in 1942 a single seat observation gyro kit for used from German U-boote. The purpose was to discover Allied ships and the FA-330 could see them from about 20 miles when towed 120 meters up with a cable from the boat. Some 200 were manufactured but their success was very limited.
FA-330
This Bachstelle was seen at the war museum at Duxford (U.K).
Photographed 2015 by Cees Hendriks (C) Copyright IPMS Nederland
A few scale models exist: in 1/32 FLY has a kit, in 1/48 again FLY but also Kora. In 1/72 Pavla and Blue Rider had kits.
This walk around was first created May 2018 by M. de Vreeze; note the Copyright!