The most famous of three is the one made by Graham Bartram, that's so used in media that it's almost an unofficial flag of Antarctica. Blue to sea, white to ice, forming Antarctic map. Simply beautiful, but we shall admit that this colors aren't the most distinguishable in polar landmark. The good point is that the flag is very neutral, and it refers directly to Antarctica.
The Whitney Smith's proposal is, at least, very visible, because of its orange color. But isn't a very good design, for me. The "A", for Antarctica, is easily removable. The map of Antarctica isn't very visible: a great number of people, at first sight, think it's a bowl — with some reason. The hands, that symbolizes the peaceful use, is a good idea, thought. At all, I think it isn't totally adequated.
The Dave Hamilton's proposal is known for being used in fake "Antarctic Dollar" notebanks. From top to bottom, the colors mean: the sky; the aurora australis; the ice and sea. The symbolism and colors are great, but the right canton hardly will be seen in that windy continent. (There's any astronomer to confirm that Southern Cross looks like that in South Pole?)
The three designs have problems, but can be worked to look cool and visible at ice at same time. What is your favorite?
What's your opinion? Do your comment!
Looking for Antarctic flags, I found this funny Flicklr about flags.