Ok, I suppose that now that is very true, although I think that would only apply on some maps. I still think there should be an actual straightforward bonus. Being the first I circumnavigate the world is a big accomplishment (unless you're Polynesia) and was seen as a bug accomplishment in history. 1 extra movement for naval units sounds appropriate, but they could also make it a bonus say to the length of trade routes. Just something to incentivize exploration.