You don't need a valve
Posted by: pblanc on Jan-02-13 4:05 PM (EST)
As Marshall suggested earlier, just thoroughly burp the suit at the put in.
Find an area where you can stand in water about waist deep, then squat down in the water so that the suit if fully immersed except for the top of the neck gasket. The water pressure will force the air to the top of the suit. Just pull the neck gasket away from your skin enough to allow the air to escape. You may need to stand and squat back down a few times to completely burp the suit.
If you do this the suit will cling to your body in such a way that it looks as if it was subjected to a vacuum.