USA HISTORY

Detailed explanation-1: -Tools such as an hourglass, a quadrant, a compass and a nautical chart were vital for effective navigation.

Detailed explanation-2: -In their earliest use, compasses were likely used as backups for when the sun, stars, or other landmarks could not be seen. Eventually, as compasses became more reliable and more explorers understood how to read them, the devices became a critical navigational tool.

Detailed explanation-3: -Three tools are of particular importance to this time period: lateen sails, the astrolabe, and the magnetic compass.

Detailed explanation-4: -One of the oldest navigation tools, leadlines were used to determine the depth of the water under the ship. A leadline is a long rope with a lead weight attached at the end. Sailors dropped the line and recorded how much line it took to reach the bottom of the ocean.