Check out this geeky watch, the Astrolabe Watch.

The primary use of the mariner’s Astrolabe was to find the latitude of a ship at sea. In use, the Astrolabe a mariner would use is suspended (above eye level) and the altitude of the sun or a star above the horizon is measured using a rotating disc.

The measurement is taken when the sun or star is at its maximum altitude. The star’s declination of the sun’s declination for the day can be found from an almanac. The latitude is then found by solving the equation latitude=(90 degrees – measured altitude)+declination. The term (90 degrees – altitude) is called the zenith distance.

The Astrolabe Watch is available for $69.99 from Think Geek.