Frenchie,

"if lateral gap is under 30% rigs span "

I am unsure what you man by the terms lateral gap and rig span.

Does this mean if the distance between the masts is under 30% of the boom length?

Thanks

Gareth

P.S. here is another good looking biplane boat http://www.mko.freesurf.fr/innovoile/historic_e.html