Cue the white-knuckle grip. This poem begins, and remains, in the tense state of waiting out a storm. It's a meditative poem (no, nothing to do with yoga), meaning that it's all thinking and no real action—apart from the violence of the storm in the natural world. Marinate on that for a minute.
What we get are largely imagined images and actions—a whole lot of intense mental preparation for an intimidatingly blustery storm, equipped with hurricane-force winds and whipping sea spray. If you thought the Three Little Pigs were scared of getting their house blown down, this poem is another step up in the fear-of-gusts category. Heaney has us hunkering down with all of our canned goods and candles in this one.