What are ship rutters, and why were they important in western civilization?

Question

What are ship rutters, and why were they important in western civilization?

Answer 1

Rutters were the sailing directions from one point to another. The would have landmarks, distinctive sea condition, or whatever the ship captain thought important. At the point in time rutters were used longitude was impossible to compute.

The importance to civilization lies in the ability to trade.

Rutters were closely gaurded secrets.

Answer 2

I believe that's 'rudders' and the more they advanced, the better they controlled the ships. Better controlled ships could go farther, be larger, and were more easily controlled, expanding trade.