Christopher Columbus used tools like maps, charts and magnetic compasses on his journeys. He also used celestial navigation to measure his latitude.
While attempting to use celestial navigation, one of the most important tools used by Columbus was a quadrant. A quadrant is a tool used for taking measurements of altitude. Unfortunately, celestial navigation proved to be difficult for Columbus and he often ended up with false readings.
Columbus used a variety of other tools on his journeys. He used a sandglass to measure time and a nocturnal, which was a tool used to tell the time of night by the rotation of the stars.