Preventer on a cat ketch

[Scott Dunsworth]

I haven't heard this subject discussed on the forum yet or maybe I missed it somewhere.

My brother and I were sailing a few days ago and the wind was very light and shifting 20 to 30 degrees constantly. With the sails wing and wing they wouldn't stay put on a down wind run, not to mention the power boats shaking everything up. My brother said why don't we rig a prevent-er like I do on my sloop? I thought about it for a second and said why not. So I rigged a line from the end of my spirit to the bow cleat for the main and from the mizzen to a cleat mid ship. It worked wonderfully. The power boats were no longer as much trouble and the sails stayed in place. So now that the sails were locked in place I went below to get my stay sail with intentions of trying to pole it out and found that I had left it at home .

The bottom line is, this ever learning sailor learned something new that day. Instead of fighting to keep the sails out on a very light day we were making way at 1.5 to 2 when before the prevent-er were fighting to keep the sails out and going nowhere most of the time. The wind was so light that the weight of the sheets would pull the sails in without the prevent-er in place. If I had my staysail we might been able to get another mile per hour out of her.

Just something to think about on those super light wind days. This probably is old news to you seasoned sailors but it was a gem to me.

Scott

[Scott Dufour]

I do something similar with the mizzen, and use my extendable boat hook as a wisker pole for the main so I don't have to go forward. Very useful.

[Hirilonde]

Preventers are very useful at times. They can also be very dangerous. Having a plan to deal with a back-winded prevented sail is a good idea. This may not be necessary in light winds, but light winds don't always stay light.

[wkisting]

Interesting, I've not had the problem of keeping the sails out in light winds. Do you know the trick of sitting on the leeward side to deliberately induce a bit of lean off the wind? Even with just one person--certainly with two--it almost always induces enough lean in our CS20 to keep the sails held out by gravity. Then you can sheet in the main and mizzen to the desired angle and they usually stay put while sailing at any reasonable angle to the wind. The lean also helps each sail's belly fill out by gravity, which helps the boat make more speed in extremely light winds (I guess because less of the wind pressure is wasted on having to fill the sail. Not sure, but it works).

On the other hand, in the few times we've been through rough powerboat wakes, there is a lot of flapping and sprits knocking against the mast. Is that what the preventer helps with? We don't encounter powerboats but once in a blue moon, but I can see how that might be a problem if you're on a smaller body of water or confined area where you encounter them routinely. If the sails aren't drawing a good wind, we've had a steep wake make our masts/sprits start clanging like church bells, but only for the few seconds it takes to plow through it.

[Scott Dunsworth]

In light winds I have and do lay to the leeward side on a beam reach to keep all three sails full. But down wind or a reach where I want the sails wing and wing that just doesn't work. Any way its not something I'll use a lot but it will be kept in my tool bag for certain conditions.

Scott

[Bob Reynierson]

Interesting thread. I sail a WWP 15 and am thinking seriously about building a CS 17. With the sloop rig on my boat I don't try getting the sails wing to wing unless I'm on a run, and then I am more worried about an unplanned Jibe than keeping the sails wing/wing. As I understand it the purpose of boom preventer is to prevent an unplanned jibe on a long downwind run. I noticed you said you were on a downwind reach (broad reach?). I have only sailed a cat-ketch (a CS 17) once. I thought wing to wing would be something that would only be practical on a run, or maybe a training run, and that on a downwind reach the sails would want to be on the same side just like a sloop rig. I have also read (on the B&B site I think) that with a cat-ketch unplanned jibes are not a big deal, nor does the foresail tend to luff in the annoying manner a jib often does on a run. What is the experience of those of you who are sailing cat-ketch rigs?

BTW I often sit on the leeward side along with my crew in light winds and find I get better performance, I just try to stay sharp so that we can quickly switch sides and/or depower the sails in a gust. I think I tend to use that technique more on upwind courses as my boat seem to do better sailing upright when running downwind. I sail the inshore waters around Cedar Key, FL and share the waters with numerous power boaters. If a boat wake seems particularly problematic I am usually able to briefly alter my course to cross the wake at an angle, which cuts down on the rock & roll effect substantially.

Bob Reynierson

[Scott Dunsworth]

If I am on a broad reach I usually have the sails on one side. But on a broad reach where the wind is shifting around a bit from a broad reach to a run I'll usually run wing and wing.

Hope folks don't misunderstand I was using the preventer in VERY LIGHT winds. Normally, I use all of the normal ways of thinking for sailing light winds. I don't have to use boat momentum turning into power boat wakes with the preventer.

Your right an accidental jibe is not normally a big deal but it doesn't help forward motion ether. I am not advocating the use of a preventer to prevent accidental jibes, but to merely help keep the sail full and drawing in light winds.

Scott

[Alan Stewart]

Often when sailing in a deep reach the main will become mostly blanketed by the mizzen. The sheet will go slack and its obvious that the main just isn't really pulling. This tells me that I could be going faster with the main on the other side. I'll pull it in and give the sheet a jerk while simultaneously turning down just a bit to get it to fill and then let her fly out while coming back on course. Sometimes I'll let it fly past 90 degrees on the windward side to help keep it out there otherwise it can easily just flop back over which as stated is no big deal especially with no footed boom to worry about.

In our CS and in the 17 I have found that sitting to leeward to induce heel in light air makes a big difference. It's all about wetted surface area at that point and a planing hull which the CS's are have less wetted surface when you heel them a little. Getting the transom out of the water also makes a huge difference. In a LIGHT wind run have someone go up to the bow and compare GPS speed with them up there and sitting in the back. Note: This does not work when planing in heavy wind.

[Hirilonde]

If speed over a certain distance or leg of a race that is down wind is the goal then virtually all boats do better tacking down wind over a dead run wing and wing. I only even consider a preventer when on a broad reach in light winds when wave action is flogging the sail. I never sail wing and wing.