how to signal "I'm not okay"

In freediving, we have a thing called the surface protocol, which is designed to make you prove that you're in control and okay after a dive. One of the aspects is that you have to give an okay-sign by making an 'O' with your index-finger and thumb. The following picture is close to that, but such a gross distortion that it's more 'not okay'.




(another Lafforgue picture, found here: http://www.flickr.com/photos/mytripsmypics/2906854149/sizes/o/)