"I can take pieces of cork with me and wrap round them so as to keep their faces just afloat.

I should only want something that would hide their faces." "A hatch might do," Pierre said.
"The very thing!" Harry exclaimed with a fresh ring of animation and hopefulness in his voice.

"The very thing! Of course there would be a hatchway to the forecastle of the lugger.

We might get that loosened beforehand, so that it would float off.

What is the size of such a hatch ?" "Some four feet square, monsieur." "That will be enough," Harry said; "but how high would a hatch float out of water, because there must be room between the top of the water for us to breathe as we lie on our backs.