system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How Mercator Projections are better for navigation than other projections (like equal area projections)?

I've read that although the Mercator Projection distorts the relative size of continents, it is still used for navigation.


What would the same plotted course look like on the Peter's Projection versus the Mercator Projection?
gpt
The Mercator projection preserves angles in a way that navigation paths are shown as straight lines. 

That makes it very practical for navigation: measure the angle on the map, take course on that direction, and you will arrive to your destination.

Preserving angles also makes the Mercator projection to preserve local aspect ratios. That means that although landmasses appear deformed if they are too far apart (Greenland is actually as "tall" as Australia, not as big as Africa), they tend to appear with more or less the correct shape themselves. This is the reason why Google maps uses the Mercator projection.