What is the correct verb (or phrase) to describe the action of reducing a boat's sail power in a heavy storm? So far, I've only come up with reefing the sails, but that refers to the furling of the sails around their respective beams. This is a rather slow process; I'm looking for something that refers to a quick, decisive action taken in an emergency – for example, when the wind shifts suddenly or the boat threatens to capsize from too much force exerted on the sails. Personally, I would call it easing up or letting up the sails, but that's only a landlubber's guess.