An hour later, Charlie sat aboard Bill’s amphibian which now lay moored to a sea-anchor a quarter of a mile to leeward of the _Merrymaid_. A hundred yards from the plane, the gray submarine rocked gently to a long Atlantic ground swell. Charlie, a pair of field glasses glued to his eyes, focussed them alternately on the yacht and on the deck of the submarine which was crowded with men.