How about "Groundswell"?
It refers to a kind of wave, as well as a change in people's views or behaviour (usually viewed positively). "Grounds" also has a relevant meaning as in "grounds to believe", without being a blatantly distasteful pun.
Yeah, that would be a great name, not /sarcasm
I don't mean to pick only on this proposed name, but it sounds like most commenters are seeing the naming ideas from the perspective of insiders, or from the perspective irrationally in love with their proposal.
There are probably dozens of names like Groundswell and Waterline that have clever connotations. Given humans' propensity to over-associate, this is hardly surprising. I do see a distinction, though, between the two: Waterline has a more immediate / clearer physical image, which is definitely a plus.
The Singularity Institute wants to spin off a separate rationality-related organization. (If it's not obvious what this would do, it would e.g. develop things like the rationality katas as material for local meetups, high schools and colleges, bootcamps and seminars, have an annual conference and sessions in different cities and so on and so on.)
We can't think of a name for this organization.
We can't think of any names that seem good enough to be audience-tested.
We don't have any ideas good enough that we'd want to mention them in this post.
Help.