Friday, April 18, 2014.
Christopher Columbus's NavigationSailors in Christopher Columbus's day used what is called 'dead reckoning' to navigate. This system works by establishing a point and gauging the direction and space from that location as you move. This then requires one to start from a known point and work out from there. For this technique to succeed you required a measuring device to calculate how far you've gone which was usually done with a magnetic compass.
Christopher Columbus is the earliest captain that we have comprehensive logs outlining his journeys. Not to say that others didn't keep records but his are the earliest that we currently know of. Unfortunately after his initial voyage most of the meticulous information he kept track of was lost.
In the days of Christopher Columbus driftwood would be dropped overboard to determine their velocity. The direction-finder would start counting to a specific rhythm as the driftwood passed a starting point. Once it hit the end point on the vessel the direction-finder would use a formula to work out the pace of the ship from his count. The ships velocity and measurement of space traveled was taken hourly and recorded with a simple peg-board system.
Christopher Columbus mainly used 'dead reckoning' to travel but it is noted that some attempts at what is called 'celestial navigation' were made. History suggests that the use of this other method for Christopher Columbus generally failed due to unfortunate situations and a lack of knowledge about the method. Celestial navigation utilizes the sun, moon and stars to work out location and direction. The Mediterranean Sea was unhelpful in using this technique to work out latitude because it never really changed much even when you were in different places. So it wasn't till much later that sailors going longer distances made use of it.