The mariner’s astrolabe was a disk with inlaid numerical data and star positions used to help determine a ship’s latitude while at sea.

Although first developed in the 1100’s, a true compass was perfected in the early 1400’s, which gave explorers an idea of true North at all times. It featured a 360 degree face with a needle that always pointed North.

The sextant was used to measure the angle between two objects, which helped to better pinpoint navigational positions, and later helped provide detail for maps.

The rudder of a ship was nothing new, but it was moved from the side of a ship to the back of it to help with steering in the late 1400’s.

Iron begins to be used in the building of ships, particularly in the construction of hulls, in the 1800’s to provide strength to ships and helping them withstand long journeys.