Mariner's Astrolabe

Astrolabes can be used for navigation in unfamiliar or featureless locations. To use an astrolabe, the holder must be trained in Survival. By spending 1 minute to measure the height of the stars and planets, a holder who knows the time and date can determine the latitude, and a holder who knows their latitude can determine the date and time. An astrolabe also grants a +1 item bonus to checks to identify celestial bodies. A standard astrolabe functions only on steady ground.

A mariner's astrolabe contains additional stabilizers that make it suitable for use on moving surfaces, such as the deck of a ship.