Armadan Compasses are only created in one secret facility located on the floating pirate city of Armada. Being a city of tethered ships, Armada constantly maneuvers its way around the oceans of Bas-Lag. The only way for the pirate inhabitants of Armada to find a way back to their mobile home is by use of an Armadan Compass. The needles of these compasses are embedded with a special crystal fragment that makes them point back toward the source crystal on Armada.
"It would be extremely dangerous for Armada if an Armadan Compass fell into the hands of one of the other of Bas-Lag's major powers."