If you were trying to cross a river with the shortest possible time, would you aim your boat slightly upstream, directly across the river, or slightly downstream?
I was originally going to say aim downstream but I'm now wondering if the direction wouldn't matter (because there isn't a specific point that they're aiming for). I'm not sure though.

Question

If you were trying to cross a river with the shortest possible time, would you aim your boat slightly upstream, directly across the river, or slightly downstream? 
I was originally going to say aim downstream but I'm now wondering if the direction wouldn't matter (because there isn't a specific point that they're aiming for). I'm not sure though.

anonymous · Answer

This is a vector problem. It depends if there's wind. If the wind is blowing west, then you'll want to point your boat east. And if the wind is east then you'll want to point west. If there is no wind or current then point the boat straight. But this also depends where your boat is and where the point across the river you're trying to get to is.

vincent-lyon.fr · Answer

If you do not mind where on the other bank you might land, then it is as if the river were still.
So the answer is pretty easy.