By the way they drove or rode back and forth, we could spot the "spotters."
I left on the six o'clock train, after throwing the spotters off.
The Navy used these balloons as spotters for submarines and mines.
There were no “spotters” on coaching lines as on street railways.
I countered on him, and saw instantly that the Whipple end of the crowd hadn't known of Dykeman's spotters ...