Changing Width of Sailing Catamaran

That's not unusual.
Are the transoms running completely dry when you observe that turbulence?

 

Leo, Yes they are running dry. I have little experience with wind powered hulls so it's all new to me. I can actually hear things. What a concept.

 

Rob,

I am a little concerned with the perception I might be slamming your new boat. Please don't take my suggestions that way. I have no sailboat to play with right now, having just cut up and thrown away a Hobie 16 and a Tornado. Talking about yours is the next best thing right now.

The noise at the rear has to be directly related to the weight of the boat, and the weight at the rear. As you said moving things forward is the easiest way to fix some of that.

Hollow wooden crossarms can reduce weight by up to 50% of a solid beam. If you did nothing but saw the rear beam up and glue it back together you could get rid of weight on the transom. You would also keep the wood look of the boat.

My Tornado had 2 - 3/8" bolts in the end of the fwd beam on each side. Those would keep the boat square in any 3' swell you will sail. Especially with the small sail area.

Have fun.

 

No worries. Comments are good. I'm reviewing photos from vacation . The boat sits really low in the stern. Lightening the aft cross member and maybe shaving some meat off the deck framing would shed some weight without compromising strength. Creating a boxed beam would definitely do the trick as well. I'm in illinois so send your scrap hobie sails and rudders my way.

 

The reason I bought and then scrapped the Hobie was to get the sail rig for a to be designed trimaran. I'd be happy to give you the trailer (but you don't need it) since buying tires for it seems to cost as much or more than I can sell it for.

The best way to have an approach for weight reduction is to weight everything separately, when you get a chance.
Your deck framing has a center of weight all behind the main beam. Removing it all will have the most effect. If you want the wood look you could put a 3" x 1/4" cedar "bumper strip" along the gunwale edge and finish it bright. Not very heavy and still wood.

 

Hi all. Does anyone know how to upload a photo album on picasa? I've created the album so you can see the cat under sail but cannot figure out how to upload to the web.

Rob.......

 

Rob,

Can you get to the screen where it says "Featured Photos"?
Once there, along the top, the last selection box says "upload". Click it.
Next screen says Album Name in the upper left corner, type in a name you choose. Then in the center it says "Select photos from your computer". Click on that box. You should be able to select one at a time or several.
Once that is done hit OK in the lower left, then my photos in the upper line.
Now open the album you named, select the photo you want, click on the photo until you can see the photo full sized with no blue haze over it.
Then right click on the photo and select "copy image location"

Now go back to the boatdesign thread, hit reply, select the image icon, and paste in the image location you copied. Finish your text and post. You should see the image in your reply.

Good luck