Searail 19

300kg empty weight.

Small, , sharp floats ( 200-250 liters ?), gullwinged beams.--- Goin` down--goin` thru--unstoppable--poppin` up.

https://plus.google.com/photos/1138...53923120625025/5730662672200665346?banner=pwa

https://plus.google.com/photos/1138...53923120625025/5730662865792892322?banner=pwa

https://plus.google.com/photos/1138...53923120625025/5730553979855707298?banner=pwa



Goin` down--goin` thru--unstoppable--poppin` up, Chris White:

"Discovery has low volume floats, in stark contrast to the more recent tri's. In this size boat, where you can hike out and the weight of a body or two to windward makes such a large difference, the low volume float seems to work well. The boat is very resistant to capsize. In a severe knock down the leeward float gets punched under water relieving the gust and then pops back up to sail away like nothing happened. To date none have capsized and some Discoverys have sailed a great deal in very windy conditions. Sort of surprising, and somewhat unexpected. I'm NOT claiming that you can't capsize it, only that she's very forgiving."

Source:
http://www.chriswhitedesigns.com/tri.../discovery_20/

See here:
http://whatiexpect.in/index.php?option=com_video&Itemid=148&video=na_0QJjOya0

Much much better here, a must have seen:
http://www.youtube.com/watch?v=39XjhgDkmyk

Bigger unit, also low volume floats, Newick Val modified (seagoing; remember "Third Turtle", second in OSTAR):
http://www.youtube.com/watch?v=PSxlaAnjOrk
http://www.youtube.com/watch?v=dgTUTJtCM_E&feature=endscreen

High volume float, `cause of deck area and volume stoppin`, no pitchpoling `cause of massive volume in the bow sections, heeling, capsizing:
http://www.youtube.com/watch?v=bMoHhilUSoU


pogo

 

More here on Sea Rail 19 and other under 20 tris: http://www.boatdesign.net/forums/multihulls/small-trimarans-under-20-a-43650.html

 

I own a supernova trimaran and it's incredibly forgiving you can really punch those little floats under without ill effect I often sail it singlehanded and with my wife as with two average sized males it's a bit overloaded unless it's really windy.

I can right the boat quite easily singlehanded with the centreboard out but if you were a real lightweight it may be beyond you without a righting rope not unlike some larger beach cats I guess. I've never managed to capsize the boat in normal sailing (even when it's really windy) but have capsized it intentionally to see how difficult it is to right.

I can only imagine that it was really blowing a gale when they did the photo shoot for the Supernova manual or the crew were midgets because I've never had to hike off the boat or use the toe straps even in 30 knot gusts and the crew normally doesn't get out of the cockpit. It's not an insanely large sailplan and that actually translates into a nice balanced craft that is a bit underpowered under 5 knots TWS. The payoff though is you can easily balance the boat on the centre hull with the float just kissing the water and keep going when beach cats like my old mosquito would be stationary.

From a performance angle I can see that you would take a hit but the low volume floats let you really push hard in gusty conditions where you would otherwise reef or call it a day. Like everything it's a compromise between performance and safety as with lower buoyancy floats the boat is less "stiff", doesn't stand up to it's sail as much and exhibits handling characteristics more like a monohull. On large boats where the crew weight is a lower percentage of the overall weight I'm not sure it makes as much sense.

You can see with the Iren's trimarans that they are going for a smaller float lower drag type solution and also the MOD70 trimarans but I would imagine in % terms they would still be quite high maybe 180%- 200%? I found it interesting too that the new VPLP Prince de Bretagne trimaran has gone with a more elliptical type hull shape for a more gradual uptake of buoyancy and less slamming and foil assist to reduce WSA, back to the future in some ways.