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-   -   Precision 15 with or without keel (http://www.sailnet.com/forums/sailboat-design-construction/71929-precision-15-without-keel.html)

iowapuddles 02-08-2011 06:46 PM

Precision 15 with or without keel
 
I'm considering getting a Precision 15. Basically I want something small (and stable) that will fit the family to head out on light days on iowa lakes. Goal 1 is fun but a close second is to help my wife get the "feel" for sailing so we both feel comfortable to take bareboat vacations to the great lakes or the gulf. I also want something that a friend and I could take out on windy days and have some fun.

I think the precision 15 fits the bill pretty good. The only thing I'm not sure of is if I should get the keel or centerboard version. The center board draws 3' 8" and the keel 1' 9". I don't have a depth problem at any local lakes with either boat. The keel will be harder to launch, but still should be pretty easy at normal boat ramps and will still fit through my garage door.

I know I'll be sacraficing some windward performance with the short keel on moderate days and will be dragging around more weight on the really light days, but I should get more "stability" (valuable with family on board). Problem is, the keel only weights 250 lbs and is short. I've run some rough numbers based on a hand sketch and at 10 heel me and my wife (~350 lbs total) sitting on the coaming are a 8x bigger righting moment than the keel. At 20 we are about 4x bigger.

So the question is... will this little keel really give me that much more stability?? The nice thing about the keel is, the more it heels, the more the righting moment, but the problem is the magnitude is so small. Our weight (assuming we don't move our bodies) actually provides less righting moment as the boat heels. Of course, we can move our bodies and we don't have to move very much to make a big change in moment.

Any comments? do my numbers sound about right? Is there a good reference out there that talks about this kind of stuff (short of a 500 page text book on nautical engineering)?

By the way... I'm an engineer, a normal person would just go out and sail them both and figure out which one felt best. It would, however, be kinda cool to predict which one will be better :D

PeterSailer 02-11-2011 04:27 PM

If you want to help your wife to get the feel, I would definitely go with the keel version. Simply because when she is gonna step aboard the boat will feel more stiff end the sailboat will feel less tippy (before you raise the sail).I'm not familiar with those sailboat but you might have more interior space with the keel version cause you won't have the centerboard trunk in the cockpit or cabin.

Even with the small keel, when the wind will be stronger, it will get exiting.

Now if your thinking to single hand your sailboat that extra 250lbs down below will be welcome because your not gonna have anyone else to sit on the rails...

I once when out with my small nordica16 singlehanded and I sailed around with a friend who was sailing in a small victoria18. They were 2 in the victoria. And then the wind got up, they were heeling just a bit(they were both sitting on the comings) while I had the rail in the water the hole time, some time i had to let go the main sheet... oh yeah and i had no place to hove to to take in a reef cause we were sailing in small channels... It was fun anyways ;)

Welcome to sailing and sailnet, and have fun learning the ropes.

iowapuddles 02-11-2011 05:01 PM

After I wrote all this up, it dwaned on me that at the dock it will help a bunch. In the wind, you and the keel are on the same side of the center of bouancy, so the moment arm matters the most (since the keel is so light).

At the dock, you and the keel will be on opposite sides of the cob, therefore you should really notice improved stability.

PeterSailer 02-11-2011 05:04 PM

exactly

iowapuddles 02-14-2011 04:49 PM

well.. I bought the CB version. the dealer had a hold over 09 for about 4k less than what it would take to order a new keel version. He confirmed that the keel is basically a marketing ploy. not really any more stable under sail if you know how to handle the boat. Mostly just more stable at the dock or at a mooring ball. I'm curious what kind of a dinghy you'd take out to a 15' boat at a mooring ball? ;-)

pdqaltair 02-14-2011 05:04 PM

There is a very active Precision forum.

But come back here when your done!

iowapuddles 02-15-2011 04:56 AM

really? There is the owners website, but not forum. Trailer Sailor has a precision part of their forum, but the low tech UI drives me nuts. I can't follow those threads! Also, not much P15 talk on their site.

There are alot more capri 14.2's out there (which is why I almost went that route), but the P15 seemed to be a better boat.

pdqaltair 02-15-2011 05:24 AM

Quote:

Originally Posted by iowapuddles (Post 698238)
really? There is the owners website, but not forum. Trailer Sailor has a precision part of their forum, but the low tech UI drives me nuts. I can't follow those threads! Also, not much P15 talk on their site.

There are alot more capri 14.2's out there (which is why I almost went that route), but the P15 seemed to be a better boat.

That's the place. Just ask the question.

I've sailed the P15 and the P185; they are very well built boats.


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