As of the time that I calculated (18th March 2017), A very brave Australian woman by the name of Lisa Blair was circumnavigating the antarctic continent all by herself in nothing but a sailboat. As of the date above, she was out at the coast of Argentina and was sailing at about 7.2 knots.
If the earth was the shape AND the same projection flat earthers claim it to be, it would take her MUCH longer to reach the area that she was at on the 18th of March. According to a YouTuber by the name of CoolHardLogic in his flat earth debunking video, the circumference of the flat earth in between Argentina and Antarctica all around the edge of the planet between the landmasses is about 103,700 kilometers. This gap between Antarctica and south america all around the edge in a circle is pretty much Lisa Blair's entire path for her journey.
On the 18th of March, she was 52% and 55 days through her journey on her way back to Perth Australia. 52% of 103,700 is 53,924 so she would've had to have covered 53,924 kilometers in only 55 days... but this is utterly impossible, as I mentioned that her average speed was about 7-8 knots. Let's be generous and say that she can remain a constant speed of 10 knots... unfortunately, it would take her about 121 days to do 53,924 kilometers instead of the TRUE 55 days at a much smaller distance and a slower speed.
In a nutshell, getting from Perth, Australia to the coast of Argentina in 55 days in a boat travelling 10 knots or less is utterly IMPOSSIBLE on an Azimuthal Equidistant Projection. It can only be explained on a round earth because her circle around Antarctica is smaller the closer to the south pole she is.
Here's her GPS log before failing her mission and having to go to cape town when her ship broke. (Unfortunately)