Ummmm.... don't think so.
However, that is not what I was debating.
You are talking about the most extreme endurance tests. I am talking about the ability to swim, and avoid drowning.
Not every one is good at the long jump, but everyone can do it. Same with swimming. Fear is the only thing that makes people believe they 'cannot' swim.
But this discussion was rooted in swimming requirement for Navy Seals.