I think for maximum exploration, the worker should go W, N, or E. E will uncover the water and tell us if it's salt or fresh, and also uncover 7+ tiles. N and W will uncover at least 5 tiles (more if there are hills or mountains beyond those 5). Moving E is problematic if it doesn't show anything good because the worker will have to move 2 more steps back to a good tile to work. W will show some of the grassland and see if there is more grass and river that way. N is going to uncover more plains, and puts the worker on a workable tile, but I believe ainwood said this game will be on Monarchy (think it was in the COTM/GOTM difficulty thread), so we won't need the lux connected until we grow to size 3.
Having said all that, I think I probably will actually move the worker E, just because it uncovers more fog. If I don't see anything I will likely move the settler W, especially if the water turns out to be coast (to allow more distance for coastal towns in RCP ring). This will also put more river tiles in the capital radius. Then the worker will probably head for the BG (SW,W to uncover one more tile).