A warrior and a scout swim at same speed.
Spoiler :
The "continent" that Greece and the Iroquois were on was accessible without Astronomy. You could get there without going over ocean tiles, by heading NW from Sidney (which was the City-State immediately to the W of the starting spot).
But what I really meant to say is that Scouts can do a good job of exploring territory once you actually get there. Not only do they move unhindered over rough terrain, they have +1 movement and +1 visibility promotions which help even more.
And getting a Scout to 30 XP (for both promos) isn't all that hard. If there is a Hill and/or Forest next to a Barb camp, you can park your Scout there and the Barb Warrior will usually attack you (eventually). Also, I try to find Barb Triremes and let them attack my Scout every turn for +2 XP while I regen +1 HP every turn (the Triremes will do 1-2 dmg per attack it seems).
But what I really meant to say is that Scouts can do a good job of exploring territory once you actually get there. Not only do they move unhindered over rough terrain, they have +1 movement and +1 visibility promotions which help even more.
And getting a Scout to 30 XP (for both promos) isn't all that hard. If there is a Hill and/or Forest next to a Barb camp, you can park your Scout there and the Barb Warrior will usually attack you (eventually). Also, I try to find Barb Triremes and let them attack my Scout every turn for +2 XP while I regen +1 HP every turn (the Triremes will do 1-2 dmg per attack it seems).