It's not to say that you can predict everything that could go wrong, but if that one iceberg is still there and it blocks the only route to port (like, what you want to do is still illegal), probably not too smart to jump in a canoe headed that direction.

If you look at the icebergs that were in the way before and they're gone now, it doesn't guarantee success or mean there aren't other obstacles, but at least you know that the previous reasons for failure aren't still insurmountable.