On a whim after starting to read the 16 Emergency Landings proving flat earth book I thought, definately the ships would have to follow the same rules. This is the search image I found (an example of many). Title is "A Year of Global Shipping Routes Mapped by GPS - Wired" Now, look at all the curves! The top ones makes sense if you think of the true map of the world. But what abou the ones further "south". Why do they curve away and not inwards as well? Hmm.