The first part is gorge or canyon. Not sure how this translates in to an insult. They do call us Insel Affen though.
ok, i know german ( i am german ) ehm schluchtenscheißer is our bad word for austrian people, as u say krauts,... to us the word schlucht means somehing like canyon
I lived in Germany for a brief period of time, and the most common insult I heard translated as 'island ape'.