[caloway]

I figured 1 second for problem identification and reaction, 1 second to roll the boat, 1 sec to roll out of the skirt and a couple of seconds to come up and orient. And that doesn't even get you out of the way.

Let's be honest, though, a paddler-turned-swimmer isn't going to be able to get out of the way fast enough to matter.

Not sure about river paddling. My experience is primarily ocean off of southern Maine and Cape Ann. The middle of the lake is pretty comparable to cape and bay paddling.