What problems did sailors have with mapping during the age of sail?

The age of sail covers a very long period. In the beginning, navigation was rudimentary. Charts were innacurate. Some cartographers filled in unknown areas with pictures of sea monsters.

However, by the time sail was giving way to steam, charts were much more accurate.

@ Liberty/Underpants: Accurate maps were made long before aircraft, using bearings, distances and trigonometry.

Unknown coasts were mapped by fixing the position of the ship and taking intersections of prominent landmarks.

Pendulum clocks cannot function correctly on a rolling, pitching ship; gimballed or not. Without the correct time at all times, navigators could not use their charts to determine Longitude.

See 'The Longitude Prize'

Well, neither Office Depot nor Staples had been invented yet so they were probably totally boned when their pens ran out of ink. Laying their hands on paper to draw the maps on was probably a huge ordeal as well. And they couldn't fly over the coastlines cause there were no airplanes so how the heck to they map those??? Birds??? I don't think so.....birds are too small to carry even a very lightweight, midget with a talent for drawing coastlines in flight and they are way too stupid to draw pictures of coastlines themselves.

Also, everybody back then had either scurvy or dysentery or smallpox or leprosy or something and I imagine that having explosive diarrhea while some parts of you are itching like mad and other parts of you are rotting off and all your teeth are falling out at the same time made drawing maps a real pain in the ***.

An inability to take accurate measurements, and occasionally, terrible navigators. Amerigo Vespucci, Columbus's navigator, once log his location as being somewhere in the middle of Belgium.