Originally Posted by
soberhawk 
I did understand it as the kind of the opposite of “urge surfing”.
This is how I see it too. White knuckling being the opposite of urge surfing.
It also means, for me, that I am still somewhat on the fence about things. When I take drinking off the shelf, there is nothing to white knuckle about.
I used urge surfing very early on when I was freshly sober. And I haven't experienced any white knuckling at all since this last attempt at getting sober.