trying to time it right , the air-gap ten-inches , eight praying that he wasnt too far down to make it to the surface , six and fighting to keep his breathing even ragged and frantic as it kept time with his racing pulse so that he had maximum air in his lungs when four jac made the break then , got his head and shoulders quickly through , his chest but as he tried to snake his waist through , he felt something snagging on one leg , holding him back .