trimaran flying on 1 ama

[rapscallion]

The seacart 30s amas displacement are something like 3.5 times the weight of the main hull.

if you have amas that are 150 or 160 percent displacement of the main hull you can still bury the ama. So what is a good minimum displscement if you are looking to make an ama that won't submarine?

There is a cool video of a kurt hughes tri on u tube. Watching that video is what got me thinking about this.

I think it depends on whether or not the design is expected to be it's fastest when flying the main hull and whether or not the ama's are designed to plane or use foil assist to reduce displacement when the main hull is flying.

[rapscallion]

I was thinking of a non foil design. I was wondering how big I would have to design an ama in order to insure I wouldn't bury it. I'd rather fly on one ama than bury her in a fantastic spray of white ocean goodness.

I suppose the seacart 30 proportions would insure that...

[Chris Ostlind]

200% is a nice place to be, Raps.

[waikikin]

Raps, a frend of mines got a nice 9.5m tri he drives on one hull, the foils & rudders are in the floats, I sailed on it four times, three times in the Wangi regatta, one race(two where very light) the main hull came clear on windward legs- the difference is cool- gets much quieter & really starts to smoke along- glad he was driving though & I reckon in that size range its a much better flat/inshore thing to do, if ocean bumps enter the equation it might get too interesting! for me, although I'm sure those with the skills & gonads for it would love it. All the best from Jeff. PS: no idea on the volume ratio.

[rapscallion]

I have Kurt's design portfolio. I never noticed this before, but his tomcat 30 design has rudders on the floats. The displacement of the tomcat's amas are greater than his other 30' designs but the boat is about the same weight. I'm thinking he wants that boat to fly on one hull. The more I learn about trimaran design the more I like his stuff.