One afternoon we had sailed out, dressed in our oilskins, and the skipper who, submerged to the waist, had pushed us off the shore through the breakers, had warned us to be back within two hours, for at that time the ebb-tide set in and, with the fresh north breeze, the strong current would make it difficult for us to land. My father had nodded as though he were thinking of something else and had long ago penetrated and computed the caprices of the gray and formidable North Sea.