This is Government document saying we can see 300 miles

PUB. (PLANNING GUIDE SAILING DIRECTIONS * * 2017 200 & ENROUTE) ANTARCTICA Prepared and published by the NATIONAL GEOSPATIAL-INTELLIGENCE AGENCY Springfield, virginia miles. © COPYRIGHT 2017 BY THE UNITED STATES GOVERNMENT NO COPYRIGHT CLAIMED UNDER TITLE 17 U.S.C. This means there ELEVENTH EDITION
This is a Government document saying we can see 300
54 The Antarctic Pub. 200
can be NO curvature of the Earth.
0.0 There is almost no dust or solid particles in the Antarctic air and the prevailing winds blowing off the continent have small moisture content. consequently, the visibility is usually very good and often exceptional, a fact which, if not appreciated, may lead the observer into serious error when judging distances. An object which may be thought to be but 5 miles distant could well be 30 miles away, and mountains have been sighted at 300 miles.