It seemed a weary, weary way to get.
But now the water grows lighter and less dense.
Jack and Harry can see about them.
Both are experienced swimmers and divers, and they always keep their eyes open under water. And now this habit serves them in good stead, for looking up, Jack perceives a huge floating mass bearing down upon him through the water.
Jack and Harry have Fleon's words, and the cruel jokes of Barthes, still ringing in their ears, and they know, alas too well what it means.
A shark.
With the energy of despair, both boys strike out, diving lower.
And now for a moment their fate seems sealed.
They discover that their rapid movements are stopped by the sack, which they have not got quite clear of, and which, puffed, follows them up through the water in their progress to the air and light.
And this, by a miracle, saves them.