Here you'll find a wonderful selection of instruments used for navigation. One of the earliest known instruments to be used for marine navigation was the mariner's quadrant. Later, in the 16th Century, the celestial astrolabe was modified for use at sea and it enabled the Portuguese to explore the world. The mariner's astrolabe remained in use for more than two hundred years. Another instrument that was used for "shooting the stars" in the 16th Century was the cross-staff, but it's use at sea was limited. Genuine quadrants, cross-staffs and astrolabes are very rare and expensive, so don't expect to see any here at Nautical Style in the near future. The 17th and 18th Centuries saw great advances in instrument design. The Davis quadrant, or back-staff, invented by the English navigator, John Davis, in 1595, was a big improvement over the cross-staff. The bach-staff remained in use for 150 years. Then, in 1731, John Hadley invented a double reflecting instrument called the Octant, which was the forerunner to the sextant.
