December 3, 2015

Dealing with heavy weather

THE WAY OF A SHIP in the sea is not as great a mystery as the Bible makes it out to be. Most of us can understand that a boat left to its own resources in heavy seas will tend to adopt a position that’s roughly broadside on to the wind.

Most keelboats will settle that way, and be quite happy, when all sail is taken down. Often, there’s a tendency, especially with sloops, for the bow to drift downwind a bit, which causes the hull to gather way and forereach. You can counteract that by lashing the helm to leeward, so that every time she tries to go forward the rudder will point her up into the wind and stop her in her tracks.  This is known as lying ahull, and works fine until conditions get so bad that your boat is being lifted by large breaking waves and hurled bodily down to leeward.

Most of us can also understand that things would be better if the boat could be made to lie with the pointy end facing the oncoming waves. Then she’d be presenting a much smaller area to the force of breaking waves, and she’d be much more difficult to overturn.

The question is how do you keep her facing that way in heavy weather without the help of an engine?  If you can keep the bow still in the water, then of course she will lie downwind as if she were made fast to a post. The sea anchor, made fast at the bow, is designed to do that, to act as a post, although it’s a post that actually moves very slowly through the water. But while it works well for boats with even, shallow draft, the sea anchor won’t keep a normal keel boat pointed into the waves, no matter whether it’s a fin keeler or a full keeler.

The Pardeys, a well known and very experienced cruising couple, claim to have kept their 29-footer pointing more or less into the waves by setting a sea anchor from a bridle, with one end of the bridle attached to the bow and the other to the stern. By taking up slack on one end of the bridle or the other, you can  of course alter the way the boat lies.

I’ve never tried this, but I have serious doubts whether normal people could manage this trick. For a start, I can’t imagine how I would be able to drag a sea anchor with its mass of small lines and its 25- to 30-foot spread of parachute material across the deck and over the side to windward in a heavy gale.

So I have never tried to lie bow-on to the waves in heavy weather. My method, in a full-keeler, is simply to lie ahull with the tiller lashed to leeward, until things get too dicey, and then to run off downwind under a storm job or bare poles. You need lots of sea room to do that, of course. A fin keeler is best kept moving at all times, but this needs a fit crew.

Some boats will lie about 45 to 60 degrees off the wind with the help of a special storm mainsail. It’s cut so that a lot of its area is aft of the boat’s underwater pivot point, the center of lateral resistance, so that it tries to point her up into the waves all the time.  But most boats these days don’t come equipped with a storm main, and few of us realize that using a third reef in the working mainsail instead doesn’t cut it, because that actually moves the sail’s center of effort farther forward, instead of aft where you want it.

 Anyway, the only real way to sort out this problem is to go out in bad weather and experiment with your own boat. The best way would be to persuade some experienced sailor with a sister ship to take you offshore, hunting for a storm, and watch what he or she does to cope with heavy weather. But I’d say your chances of pulling that off are rather slim.

Today’s Thought
Everybody talks about the weather, but nobody does anything about it.

— Charles Dudley Warner, Editorial, the Hartford Courant, c. 1890


Overhead at a Boy Scout meeting:

“Did you ever have one of those days when you felt just a little untrustworthy, disloyal, unhelpful, discourteous, cowardly, and antagonistic toward those wretched old women who always wait for suckers to help them across the goddam road?”

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)



Adventures of Salacia said...

Good post, what are your thoughts on Jordan series drogue? Here is a video of a Pearson triton that deploys a series drogue in moderate conditions. Looks like it works quite well.

John Vigor said...

Salacia, there's a lot about drogues in general, and the Jordan series drogue in particular, in my book, The Seaworthy Offshore Sailboat. The Jordan drogue is probably the most scientifically designed drogue and reportedly works very well as long as you're prepared for waves to break over the stern and flood the cockpit. A high bridgedeck is needed to stop water flooding down below through the companionway, and eventually if the wind keeps freshening you might have to cut your drogue free and start high-speed scudding in the fashion of Dumas and Moitessier. But those are exceptional conditions.
But yes, to answer your question, the Jordan drogue is a valuable aid to seaworthiness and safety and should find a place on every deepsea boat.

John V.