i once flew business on elal on the 747 and sat upstairs. since the entrance to the cockpit was located there i knew the marshal had to be sitting among us. however there werent too many of us up there, and no one fit the bill. one guy was sitting in a window seat, another was sleeping the whole flight etc. i finally asked the beefy male steward, excuse me, but i have to ask, who is the marshal and proceeded to explain to him why it couldnt possibly be anyone sitting in the cabin. he cracked a smile and pointed to himself...
on rj its very simple to figure it out. especially when im first to board and theres already a very arabic looking gentleman sitting in business...
i was actually apprehended by one of them, but i think i wrote about it on one of my tr's