What was one of the navigational difficulties in the seventeenth century?

Answer 1

Navigational aids were much more primitive then than today, where satellite-guided systems tell us exactly where we are. But in the seventeenth century, a captain who had to sail from England to the coast of Brazil and from there on to a specific island in the East Indies, always managed to get there without groping around. Even captain Bligh when kicked into a sloop to perish after the mutiny on the Bounty in mid-ocean, managed to get to the Dutch East Indies - thousands of miles away - in a fairly straight line.

But some of the difficulties were for instance: the use of a sextant to determine your location required a clear view of the sun; and no sun, no good idea of where you were and how much you had progressed. Stars guided you at night, but an overcast sky made this difficult or impossible. And while fairly accurate maps were at hand of most commercially travelled routes and countries, several other areas and routes were still poorly mapped.

Answer 2

Navigation of the seas and oceans progressed during the 17th century. The vast improvement in the telescope helped seaman chart courses through star gazing, as one example. One persistent obstacle was devising a reliable method of determining longitude. this remained a problem and there were no shortages of scholars attempting this. One mathematician, Edward Wright, made substantial progress in navigation. By 1665, a Jesuit priest also made progress in marking off major currents. This was a "blessing" for seaman.By the end of the century, longitude remained a sticky problem.