OK, here are some numbers:
If Barentz heads northwest through the jungle, it takes 6 turns (end of turn 73) until we start uncovering FoW in that direction (along with another slither along the way).
If Barentz heads southwest, we can start uncovering FoW right away
The general direction to take for both is identical for the next 2-3 turns for either of hte above options. (NW>NW SW).
A thid option, however, is for Barentz to head back to the southeast, which would take until t79 to start heading into the unknown again, and is heading into desert, where the woody2 upgrade may not be that useful.
Personally, I'm not that sure which is the best. If we want, we can wait until we get sailing on t75, and throw a scout and axe onto a galley and send it to the east to drop off the axe to scout inland and the scout to check out the coastal areas and then load back onto the galley (scout is not a requirement, but is very cheap). We can't really do this to the west, as we could be sending Zuurstof to the SE and that would uncover all of that land a dozen or more turns before the galley would get there, and the south we could send a chariot to, so we do have quite a few options as I see it, it's all a matter of priorities...