Sextant

With this tool and a map of Britannia divided into longitude and latitude, it is possible to calculate a party's exact geographic position with the help of the sun or the stars, preventing them from becoming lost. It can even help while in the deep wilderness or lost at sea, where peer gems are useless. The sextant obviously won't work under roofs or in caves.

The sextant first appeared in Ultima IV, but it could only be bought in a guild shop when asking for item "D", which was not listed, but could be learned of from by tipping Celestial, tavernkeeper at The Bloody Pub in Jhelom. In Ultima V, the sextant could be obtained from David in the lighthouse, Greyhaven, after first getting information from Buccaneer's Den. By Ultima VI, it was a standard item and could be bought from Ephemerides, the lensmaker in Moonglow.

The sextant also made an appearance in Martian Dreams, found amongst the other items in the space cannon. In Ultima VII, shipbuilders sold them, and for the first time they were usable with a map to automatically show a party's position. Its functions changed little in Ultima VII Part Two and Ultima IX.

Trivia

 * There are also golden sextants, which function identically. One can be found in the harbour building of Minoc.