Life aboard ship in the age of sail was brutal, even by the standards of the day. Ordinary sailors worked in horrific conditions for months on end for little pay and often for nothing more than just a stake in the profits of the voyage.
Easily, the cushiest job on a ship was that of navigator. Navigators were quite often hired guns who had no other duties. A navigator often needed to work no more than four hours a day. He would come on deck two or three times a day to take sightings, then return to his cabin for an hour’s worth of calculations. Compared to the physically taxing, mindlessly repetitive and dangerous work of a sailor, navigators did nothing and risked nothing.
Yet navigators often received as much as much as 25% share in the profits in a voyage. Even when they worked for pay, they received a wage many, many times that of sailors who did much more arduous and even critical work. Why did those who owned shares in a voyage, from the cabin boy to the landlubber investors tolerate paying the navigators so much?
The answer is obvious: if the navigator made a mistake, it didn’t matter how hard everyone else on the ship worked or how competently they did their jobs. The skill of the person doing the navigating determined the success of the voyage or even if anyone survived. People paid navigators a lot because if they didn’t, it didn’t really matter how much they paid anyone else.