Navigational Tools Used Throughout the Ages

Man has used many tools and method to find his way around since the birth of mankind. These tools have incorporated ways to tell direction, length, depth and time to aid in mapping areas to aid others to find their way around. The systems used have become more advanced over the years with the influence of emerging technologies.

  1. Lead Line

    • First used by the ancient Egyptians poking a stick into the water to find the depth and avoid running aground, the lead line was developed further by using a weighted rope to judge much greater depths. The rope was marked to show the depth quickly and measured in fathoms. The bottom of the lead weight was hollowed out so a glob of animal fat could be inserted which would pick up debris from the bottom to show what the boat was sailing over.

    Compass

    • A compass is a devices that uses a magnetized needle that points north floating over a compass card indicating the different directions. The compass evolved from devices such as the lodestone used for centuries by the Chinese and other devices using magnetized needles. Compasses are still used throughout the world to find direction when you have no other direction indicators such as at sea, in the air or under water.

    Ka-Mal

    • Developed by the Arabs to note how far they were from a certain point, the Ka-Mal was a piece of wood suspended on a piece of rope. The navigator sighted the horizon at the bottom of the wood and Polaris at the top. When everything lined up the ship was at the correct point to turn to port. There was a hole in the center of the wood through which a string was fixed. A knot in the string, placed between the navigator's teeth, would then set up the correct proportion of distance from the eye, and an alignment of the horizon and Polaris. Different knots were used for different ports up and down the eastern shoals of Arabia and East Africa.

    Chip Log

    • The chip log was used in the past to determine the speed of a vessel. It involved tossing something over the bow of the vessel and measuring how long it took to get to the stern of the vessel. Knowing the length of the vessel the navigator could then calculate how fast the ship was going. This was later developed further by the English, using a piece of wood on a measured spool to measure speeds and calculate nautical distances.