Rhumb lines originate from an old method of dividing the horizon into 32 fists. If you stretch out your arms in front of you with clenched fists, you can fit these 32 fists onto the 360 degrees around you.

You can even try it in a room. Let the left edge of a fist align with a certain point or line. Everything between this line or point and the right edge of the fist is the first rhumb. Place another fist to the right – that’s the second rhumb. Then, alternate moving the fists clockwise (like a compass).

When you reach the 9th rhumb – that’s 90 degrees; the 17th – that’s 180 degrees; the 25th – 270 degrees; and the 32nd rhumb covers the range from 348.75 degrees to 360 degrees, which is back to the start, thus completing a full circle. If the point chosen at the very beginning was exactly North, then after 8 fists you will have turned to the East, after another 8 – to the South, then after 8 more – to the West. And finally, back to the North.

Different people’s fists may vary in size.

P.S. The line in the snow was drawn by guides from large tourist ships. Passengers on these liners are not allowed to step anywhere the guides forbid them. It’s simply because there are many people; it’s impossible to keep track of everyone, and they are responsible for all of them.

But on yachts, there are usually fewer than ten tourists. No one hovers over them, and everyone must be responsible for themselves first and foremost. The captain explains the safety rules at the beginning.

My sailing companion carefully nudged up to the edge of the glacier to sunbathe in the blindingly white Antarctic sun.