They have lifeboats on ferries crossing the English Channel. That's not because it's physically impossible to swim the channel (it's quite clearly possible, and

They have lifeboats on ferries crossing the English Channel. That's not because it's physically impossible to swim the channel (it's quite clearly possible, and is done on a fairly regular basis), but because most people couldn't do it, and even if they could the lifeboat is a safer way of managing an evacuation from a sinking ship. I'm not saying that it is possible to jump from the ISS, just that the presence of a lifeboat doesn't demonstrate that any other evacuation route is impossible.