How Rough.
You might consider what you mean by rough. If you leave the boom attached with the sail furled along it and are getting a lot of wave action then consider this: The weight of that sail can be more than just a "few" pounds, Youv'e hefted that sail bag, remember? Now we have not only the weight of the sail but sail cover and boom as well hanging on that little attachment point at the mast. A little rock n roll can cause considerable wear over a small period of time. Personally, if I was leaving her for more than a day or two, I'd just pull the main and stow it below if I expected rough conditions before my returm. You know how rough the wind and waves are where you anchor, I don't. But in rough conditions I tend to do anything I can that will reduce wear and strain on boat. Happy Sailing, Mike
