Ancient mariners navigated around the ocean using various tools!

The compass

An instrument whose magnetized metal needle aligns itself with the magnetic fields of the earth. This causes one end of the needle to point north. Mariners used this information to navigate the ship. The Chinese are said to have invented the first compass over 2000 years ago.
A representation of a region of the earth or heavens.
This tool was once used to determine the altitude of the sun or other celestial bodies.
An early sixteenth-century instrument for measuring the altitude of a heavenly body. It consists of a square shaft and a sliding cross-piece set at right angles to the shaft. The shaft end is held at the observer's eye and the cross-piece positioned to line up with the sun and the horizon. The cross-piece marks a point on the shaft that is referred to in a table of degrees and minutes.

The quadrant

An early instrument for measuring altitude of celestial bodies, consisting of a 90° graduated arc with a movable radius for measuring angles.

The sextant

A navigational instrument which replaced the astrolabe and was used for measuring the angle between the horizon and the sun or a star in order to find out the latitude (of a ship)

Check out these great sites related to navigation during the Age of Exploration:

Create some of your own tools for navigation.