The right answer is actually ‘The Mercator projection map of the world’.

​

Mercator’s projection, which we still use today, was first published in 1569 when Shakespeare was five years old. It included rhum lines, which seafarers could use to set a steady course, and which Shakespeare refers to in Twelfth Night. Astrolabes and ship’s compasses had been around for hundreds of years, but the marine chronometer was invented by John Harrison in 1716, to help navigators work out their longitude.