Those "Germans" are riding Indians or HDs (my American ID skills are limited, but the GMC M3 Scout cars in
the background are a certainty, and they are headed in the same direction). Such a weird photo - were they
training? Was it normal to "slide in?" They MUST have been leaking fuel... but what else could you do?
Plum Island
(The image had been incorrectly labelled. Ed)

Image courtesy Tomasz Szczerbicki, author of Military Motorcycles of WWII