contestada

"The cook squatted in the bottom and looked with both eyes at the six inches of gunwale
which separated him from the ocean. His sleeves were rolled over his fat forearms, and
the two flaps of his unbuttoned vest dangled as he bent to bail out the boat. Often he said:
"Gawd! That was a narrow clip." As he remarked it he invariably gazed eastward over the
broken sea."
What does the cook meant" narrow clip"?? and "broken sea" refers to what??