The improvements in ships, weapons, clothing, rocketry and underwater techniques helped with the improvement of navigation.
Some of the world’s most important explorers used astrolabes on the expeditions to faraway lands. Christopher Columbus used an astrolabe in his historic voyage to the Americas. Ferdinand Magellan and his crew relied, in part, on an astrolabe during the first circumnavigation of Earth from 1519 to 1521. Many Arab travelers used astrolabes to navigate the desert. Perhaps the hourglass was used.
The astrolabe was probably first used by the ancient Greek astronomer Hipparchus. In the 16th century, shortly before the invention of the telescope, the Danish astronomer Tycho Brahe, whose amazingly accurate observations made possible the formulation of the present theories of the solar system, constructed an astrolabe with a radius of 10 ft. Until superseded by the sextant during the 18th century, smaller types of astrolabes were the principal instruments used by navigators.
Once out of sight of land, sailors use the stars for guidance. The octant and sextants are instruments that measure the altitude of celestial bodies to determine ship position. The octant was invented by John Hadley in the 1730s; to workout the latitude but not longitude. The octant was succeeded by John Campbell’s sextant in 1757, which could measure both. In combination with the sextant, the pocket watch was critical for timing (latitude & longitude). Weight-Driven clock was useless in a moving ship.