We passed through the narrow mouth of the cove with the ugly rocks and waving kelp close on either side, turned to the east, and sailed merrily up the bay as the sun broke through the mists and made the tossing waters sparkle around us. We were a curious-looking party on that bright morning, but we were feeling happy. We even broke into song, and, but for our Robinson Crusoe appearance, a casual observer might have taken us for a picnic party sailing in a Norwegian fjord or one of the beautiful sounds of the west coast of New Zealand.
Above is a part of what Ernest Shackleton - an arctic explorer wrote about his journey. I don't understand what "tossing waters" mean. I've never seen water use as plural. I tried to google image about "tossing waters" and find nothing. What I thought is that the sun break the mists to smaller parts of ... waters ? Am I right ?