Wednesday, June 11

Stormy Weather

By Marko Lucht

This is the time of year when we can get very unpredictable weather in Chicago. By unpredictable we certainly don’t mean to insult the prognostication expertise of such professionals as Tom Skilling or our friend Amy Seeley from NOAA Weather. But the effects can be unpredictable as well as the suddenness of the changes.

For example, we battened many things down around the boatyard here at Crowley’s in anticipation of the high southerly winds which were predicted for Monday June 2, but who knew that D and E docks would get blown away in DuSable Harbor?! 

The sudden strong straight line gusts, officially known as outflow boundaries, that often precede a severe thunderstorm are caused by a microburst, in which a localized column of sinking cold air, which descends to earth and spreads out in all directions. An outflow boundary is characterized by a sudden drop in temperature coupled with an increase in pressure, and may last over twenty four hours, sometimes extending hundreds of miles from its origin.

Illustration of a microburst. The wind
regime in a microburst is opposite to
that of a tornado.

Before leaving your boat for the day, make sure your sails are secure. A few years ago Crowley's own Jon Paige saved a boat from being tipped off its cradle during high winds when he noticed its furler just starting to unravel from nearly a hundred yards away. He heroically sprinted across the boatyard and was up on the bow of the boat before most of us realized what was going on.

When you leave your boat at the dock, it is important to have it tied up properly so that no damage will occur to your boat, the dock, or even other people’s boats. A perfect hitch is one which holds securely but is easy for you to undo when the time comes. When you know what you are doing, minimalism is key. If your dock has posts, all you need is a clove hitch with two loops. Most docks these days use only dock cleats, so in this case your magic knot is known, for some reason, as a cleat hitch. There is a right way and quite a few wrong ways to do this. I’m not the best when it comes to descriptions. If only someone were able to come up with some sort of demonstration that could be viewable by electronic devices...

The  floating dock has become the industry standard, so you don’t have to worry about water level fluctuations because the dock will be going up and down in harmony with your boat.

At Crowley’s we always use four lines and at least three fenders when tying a boat to the dock or to another boat. There is a line at the bow and one at the stern to maintain proper alignment, and two spring lines, fore and aft, to keep the vessel in place. All lines may be tied fairly tightly because, again, the boat is not going anywhere the dock isn’t. During those busy seasons in which our dock has rafts of boats four abreast and when we expect high wind situations, we will often tie a tether line on the windward side from the third boat out to the dock.

When our preferred recreational activity is so weather dependent, it is important to understand the forces of nature and to be able to work in harmony with them rather than to take arms against a sea of troubles and being smashed by them.

Happy sails from Crowley’s and have a safe and fun boating season!

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