I want to be honest about what my first reaction actually was, because the polished version of this story would have me immediately understanding the vision and saying yes without hesitation, and that is not what happened.
What happened was that Sven talked for twenty minutes and I listened and somewhere around minute twelve I had the specific feeling that I get when I encounter something that is either the right idea at the right time or the kind of idea that sounds exactly like the right idea at the right time without being it. These two things feel identical from the inside of the first conversation. The only way to distinguish them is to keep asking questions until the distinction becomes visible.
The question I asked was the one that cuts through the presentation to the thing underneath it: who is this for, specifically, and why can they not get this somewhere else? Sven answered it directly and without the defensive quality of the person who has been asked the question they were hoping to avoid.
The answer was good. Not perfectly articulated, the concept was still the early version of itself, the version that exists before the articulation has been practised on enough people for the words to settle into the right form. But the substance was correct. The person it was for was real and specific and underserved in the way Sven was describing. The thing they could not get elsewhere was the thing Naora could provide. The answer was good.

Why I Said Yes
I said yes, or rather, the version of yes that the first conversation produces, which is: I think you need to build this and I think I need to help you, for a reason that had as much to do with Sven as with the concept. I have seen ideas that are better than the people carrying them and ideas that are worse and ideas that are exactly as good as the people carrying them. The last category is the one that becomes real.
Naora was exactly as good as Sven: specific, honest, built around a genuine conviction about what the offshore sailing life gives people rather than around a market opportunity. The idea and the person were the same thing. That is the condition under which the difficult thing becomes possible.
Brilliant or completely mad. After the hour that followed the first twenty minutes, I had decided: both. And that both was the correct answer for the thing we were going to try to build. The mad part is the ambition. The brilliant part is the specific understanding of the offshore experience and the community and the human need that it addresses.
You need both to build something worth building. We had both. We still do.