Can't revive this topic often enough...
My leash-break adventure happened yesterday ("have you had yours yet?"). Got caught by a breaking wave going around a point. Had decided not to unclip (don't ask) and miscalculated. Nothing big and not a whole lot of power. Of course the boat went sideways and as I braced for getting pulled the leash just went pop. Fortunately the boat washed up on a sandy beach and I could swim in (took a while 'cause it was further out).
I'm not sure whether to be happy or upset about the leash failure. Given the outcome it may have spared me injury or an unpleasant dragging through the water. But if this had happened out in the open ocean due to a wave breaking on me it would have been not a good thing at all.
After pondering this for a bit I decided that I shouldn't focus on the leash but rather on the attachment point. It doesn't seem realistic to expect having a leash that always holds right up to the point where serious injury would occur and then releases. So I'm digging out threads about rear attachment schemes...
Pics of broken leash and intact one where I removed the shrink tube to see how the two pieces are knotted together.