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Just today my wife and I took our maiden voyage in our new to us Precision 15. We've never sailed before and had a reasonably good day - launched, sailed around for a couple of hours on the mainsail only, and made it back on the trailer without too many incidents. I have a couple of things I'm unsure about -
1. The boom vang. What does it do and how do you use it? With the boom down haul and the mainsheet it seems the boom is pretty well controlled without the addition of the boom vang.
2. Swing keel. Here in the inter-coastal, it's pretty shallow and I did drag the swing keel once before I partially raised it. What is the effect of sailing the boat if I leave the keel only partially lowered, say halfway down?

Thanks for your help. We feel like we got off to a good start but there's still a lot to learn.

Peter
 

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Peter—

Welcome to the asylum.

First, I'd recommend you get Dave Seidman's book, THe Complete Sailor. It's an excellent book, well written, in plain english with good drawings and covers a wide swathe of sailing material. About $16 or so at the bookstore.

There's a good video on the boom vang and how to use it located here. It is by a sailnet member named Giulietta, who is a good egg, and a friend of mine. He has about a dozen other sailing videos for your education. :)

The swing keel will do a few things if it isn't lowered all the way. First, it reduces your draft. Second, and more importantly, it moves the center of lateral resistance aft in the boat. This can reduce weather helm—the tendency of the boat to turn head to wind when not controlled. Third, it will probably also increase the amount of leeway (side slipping) your boat makes when sailing on a beam reach or higher (upwind).

I'd also recommend you read the new user POST I wrote, which is linked in my signature.
 

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Boom Vang and Swing Keel

1. The Boom Vang pulls the boom downward thus stretching or tightening the mainsail. You might be surprised to find out may sailors don't use it to its full potential...some don't use it at all. On a tack in light winds, you want the main to have a nice curved shape. In heavier winds however, you'll want the main to be closer to a flat shape. By tightening the boom vang, you'll be tightening the main and thus flattening it. The same applies to other points of sail. When you need a flat main, tighten the vang. There are many other things that you should be doing as well as the winds increase...tighten the back-stay for an example. To get more sailing experience, you might consider going to your local yacht club and volunteering to be crew for the local races.

2. Your swing keel provides its greatest righting moment when it is fully lowered. Basically, if you're going to try sailing with the keel partially up you should reduce your sail area. If you didn't reduce sail area, you could expect the boat to heel significantly. If you're on a broad reach or running, you probably wouldn't notice much.

I hope this helped,

Skipper, J/36 "Zero Tolerance"
 

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I sailed a couple of hours last summer on a P 16. don't know if it's close to the same boat but it handled pretty much in the same manner as larger boat like mine Oday. only thing really differen't was the lightness of the lines and smallness that made unannounced movements precarious by anyone onboard
Do try to start using the jib sail soon. You can't really appreciate how much easier a boat will sail with it until you have. Just always remember if you get over powered by the wind, to let out lines quickly! (but don't let things fly away) I learned how to sail on my first boat which was a hunter 23. was lots of fun!
 

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Boom Vang and Swing Keel

1. The Boom Vang pulls the boom downward thus stretching or tightening the mainsail. You might be surprised to find out may sailors don't use it to its full potential...some don't use it at all. On a tack in light winds, you want the main to have a nice curved shape. In heavier winds however, you'll want the main to be closer to a flat shape. By tightening the boom vang, you'll be tightening the main and thus flattening it. The same applies to other points of sail. When you need a flat main, tighten the vang. There are many other things that you should be doing as well as the winds increase...tighten the back-stay for an example. To get more sailing experience, you might consider going to your local yacht club and volunteering to be crew for the local races.

2. Your swing keel provides its greatest righting moment when it is fully lowered. Basically, if you're going to try sailing with the keel partially up you should reduce your sail area. If you didn't reduce sail area, you could expect the boat to heel significantly. If you're on a broad reach or running, you probably wouldn't notice much.

I hope this helped,

Skipper, J/36 "Zero Tolerance"
 

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1. J36ZT summed up the boom vang pretty aptly. Depending on what level of performance is being sought after, the level of attention given to the vang varies widely. High-performance racers will adjust it according to point of sail, conditions, and any number of other factors. Recreational sailors will often ignore it entirely.

The only thing I would add is that, while sailing downwind, the sail is operating purely under "push" principle, i.e., the sail is a "wall" against which the wind pushes, moving the boat forward. This being the case, maximizing sail area will maximize potential speed. Tightening the vang will do that for you. Just be careful if you have recreational boaters on board not automatically in the habit of watching out for the boom - tightening the vang inherently brings the boom lower, making it more of a potential danger for anyone not paying close attention: even a small dinghy's boom can knock an adult in the water if you're not careful.

2. The keel also has two other functions of varying noticeability. It's a pivot point for your boat: if you've got it raised most of the way, you may notice your turning is sloppy. You'll be changing the direction the boat is pointing, but continuing to move closer to your original trajectory.

In addition, it's the center of lateral resistance, which is just a fancy way of saying it prevents you from side-slipping in the water. If you've ever wondered why boats can move in any other than downwind, this is why. As a result of its being a large, fairly flat object moving through water, it's much easier for it to pass through water with its "sharper" edge, as opposed to sideways. This is why, when sailing on a beam reach or further upwind, you are able to translate motion that would otherwise simply push your boat sideways or backwards into forward motion. The further up you bring your swing keel, the more you sacrifice this benefit.

It's true what they say, though: there's no substitute for experiential learning. Have fun!

Edited to acknowledge that sailingdog pointed out the sideslipping thing as well (didn't mean to step on your toes there) and to agree with Denise - get the jib up! It'll balance the forces acting on the boat much more, you'll be able to point higher upwind, and you'll be able to move through tacks more easily. Plus, it just makes you look that much cooler :)
 
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