I would guess that if you get best possible cut for your gennaker AFAIK you need as long as possible boom. And at least in Blade the front beam is 2.35 m from bow thus 3.5 m boom will brake this 800mm rule. I guess that newer Stealths brake this too, someone could measure this?

So with gennaker booms rule "the longer the better" applies thus size matters no matter what she/boat has told you <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

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Valtteri