yes. germans pronounce "the" similar to zee, so it is not sea, just a translation mistake.The "zee" in the article is a phonetic spelling of "the" with a thick german accent. It has nothing to do the sea.
anyway, shortly, we have heard of a number 2500 but we don't know what that number means exactly.
it could mean
* the length of a map, so maybe the max map will be 2500*1500 map. i don't think this is possible.
* 2500 max hexes for a largest map. too small. if that is true, i won't buy the game.
* 2500 hexes for a std map. well, this is still a small world. even civ4 std maps were larger.
"there could be around 2500" might mean a standart world size of 2500Hexagons: the number of hexagons on the map depends on map size but there could be around 2500.
well, there are -in fact- 2 more possibilities:
* jon doesn't want to give a hint on map size (less possibility)
* jon doesn't care about max world size and just told the first number coming to his mind so 2500 number might be fabricated randomly. (more possible) maybe jon is 1 of those guys who likes to "win" the game with 4-5 cities.
the other hints like ships bombarding from 5-6 hexes just annoyed me more. this jon really seems to confuse civ with board games. ok gameplay>realism but 5-6 hexes bombardment may only be true for nukes, not frigates.
why am i annoyed? because he just tells about this 5-6 hexes bombardment issue as if it is a super feature. this is rather a high school gamer style.