Yep, it's a nautical term. The old cargo ships had these huge hatches in their decks that could be lifted off to load cargo into the holds. The battens were originally long boards that would be put over the top and tied down to anchor points on the deck beside the hatches so a storm couldn't lift off a hatch and fill the ship with water. Hence the term "battening down the hatches". On modern general cargo ships the hatches are held down with clamps around the sides. The clamps are still called battens.
Oh yeah. I have small hatches and they are battened down. This time of year they stay that way unless I need one open for something. A lot of other things are tied down as well. But this is normal up here as I'm near the mouth of the Frasier canyon and the winds tend to funnel up and down the canyon regularly. So far today we've had sustained winds of up to 36 mph but I don't know what the gusts have been. It can go over 100 mph here sometimes, but that's rare. The local private weather station a few blocks away (
http://ptlnet.net/ptl.htm) doesn't have a true gust meter as the gust has to hold for quite a while before it will register.
But it's been blowing like this for days now and does it every year in the late fall and winter. It's not so bad when it's not icy. Sometimes when the docks are covered with ice and the wind gets up in the 60mph range it can push you right off the dock into the icy water. That can kill you fast! I have steel crampons (the spiky thinks mountaineers wear on their boots) for when it gets like that. No ice now though. Its a balmy 56º outside!