For context I am a professional mariner. It is very odd that several militaries would guard Antarctica as there is supposedly nothing but penguins to guard. Certain countries or regions such as Iran, Somalia, or N Korea have strict traffic lanes that are guarded due to global politics, but who cares if I take a civilian vessel to Antarctica they several militaries won't let you even get close (60° S). However Antarctica is not the main reason I am pretty sure we live on a plane. Discovering the moon landing is fake as hell lead me to finding out all footage of astronauts in space is fake, and eventually concluding that our understanding of space and earth is fake. Furthermore working on the ocean I have the opportunity to view objects that should be obscured by earth's curvature. For instance if my height of eye is 6' above sea level, an object 20 miles away needs to be about 200 feet tall before I can begin to see it above the curve. However, I have viewed objects that defy this math many times, assuming it's a clear enough day and you have binoculars that are powerful enough. https://www.omnicalculator.com/physics/earth-curvature