Log Pose

A Log Pose (記録指針（ログポース）) is a compass-like navigational device; a necessity for traveling the Grand Line. It is a wrist watch with a glass orb sitting on top, and a needle floating inside the middle of that orb suspended from the top by a thin piece of metal or wire. Normal compasses don't work in the Grand Line due to the special magnetic waves created from each island. The Log Pose functions by recording the magnetic wave of an island in the Grand Line, and points to the next island for the user to travel to. How long it would take to lock onto the magnetic waves varies from island to island. Once on an island for the required amount of time, the recording of the magnetic wave resets to accomodate the new island. Apparently, the Log Pose doesn't work in the New World. A variation of the Log Pose is the Eternal Pose.

Log Pose Owners
Many characters throughout the story own a log pose, as it is necessary to travel the Grand Line:
 * Mr. 9 (lost to Nami, destroyed)
 * Crocus (given to Nami)
 * Nami (took from Mr. 9, and then given by Crocus)
 * Portgas D. Ace (confiscated upon imprisonment)
 * Mr. 3 (confiscated upon imprisonment)
 * Eddy
 * Urouge