'overwhelming the hulls'

[havliii]

Matt,

Finally got my SC 19 on the water. (4 sailings to date) I have been studying up on this board, reading and applying all the tips and tricks.

Can you describe what you mean by the phrase 'overwhelming the hulls?'

I typically sail 2 up, 310 total crew weight. We did sail her three up for the 'trial by fire' christening, 18-20 kts wind, 480 crew load.


Thanks,
Andy

[Kevin Keller]

Where did you see that?

[Matt Haberman]

Andy,

I think you are referring to a comment I made a while back discussing putting wings on the boat.
What I was referring to is that it could be possible to generate too much righting moment via extra weight or the addition of wings. If that situation arises, instead of flying the windward hull, you will submerge the leeward hull (overwhelming the hull volume), or maybe a little bit of both. In any case you will have far exceeded the capacity of the boat.

[havliii]

Thanks Matt, I'm closer to getting it. I thought righting moment was a good thing. At what point on a catamaran does it become a 'bad thing?'

During our test run, we were three up, only one trapped out. I was running her bow down to the lines and often past them. Our waves are notoriously short period and steep faces, so quite frequently we would bury the nose completely, if I shifted weight to the stern the wave tops would slap the rear beam hard.

What crew weight would you consider optimal on the 19 standard (my boat)? Is 500 overloaded?

Lastly, I don't quite follow all the versions of the 19, please correct this list where necessary;

19 standard, beam 8', mast 29 +/-, daggerboards
19 x, beam 8' mast 33, no daggerboards
19 xl, beam 8'6" mast 33, daggerboards

any other versions?

Thanks again,
Andy

[Matt Haberman]

Andy,

The SC19 needs to be driven with the bow down. The water should be somewhere between the waterline and the tip of the bow for best performance.

500lbs is pretty heavy. I would say that under 400 lbs is probably more reasonable for the hull volume of the SC19...

There were 3 variations of the 19.

Original or Standard = 8' Beam, 28' 9" Mast, Daggerboards
19XL = 8' 6" Beam, 33' Mast, Daggerboards
19X = 8'6" Beam, 33' Mast, NO Daggerboards