The Grigorovich M-15 was a successful Russian WWI reconnaisance biplane flying boat but due to a shortage of engines was only built in small numbers. This example was delivered to the air squadron of the Arensburg fortress on the Baltic Isle of Saarema. It was captured by the Germans during Operation Albion in October 1917 and sent to the German Naval Research Center at Warnemünde for evaluation. It was later part of Göring's pre-WWII private collection in Berlin that was transported to Poland for safekeeping due to the danger of Allied bombing. This M-15 is the only surviving example.