The answer to this is chessboard. It's made up like this: CHE for Che Guevara - the revolutionary - then SS for on ship - then BOARD for on ship and the whole CHESSBOARD - where men - i.e. pieces - ae moved.
If uou're fairly new to xwords, you perhaps don't know that Araucaria - the setter for this particular one, is reckoned as one of the most clever setters - the best, in my opinion, and his clues are usually quite tricky, but always fair, and always witty.