Perhaps I ought to explain that the crew of a ship is divided into "watches;" that is, they are separated into two lots, or divisions, one of them known as the larboard, and the other as the starboard watch. The larboard watch is on duty with the first mate, and the starboard with the second mate. I am speaking now of a good-sized craft. There's many a vessel that has no second or third officer, simply a captain and mate. The captain and mate stand watch and watch, and the crew is so small that when changes are made in the positions of the sails, or anything else out of the ordinary routine takes place, all hands are called. The day and night are divided into watches of four hours each, except the period from four to eight o'clock in the afternoon, which is divided into two "dog-watches," of two hours each. The object of the dog-watch is to prevent the same men being always on duty at the same hours. David was put into the larboard watch, while I was assigned to the starboard; Bill was in the watch with me, and Joe Herne was in David's. At first David and I were sorry that we had not been put together, but we very soon realized that it was an advantage for us to be separated. We could see quite enough of each other daily, especially in the dog-watches, and we were likely to learn more about the sea and its ways, separated as we were, than if we had been put together. Each of us had a staunch friend in his own watch, Haines in mine, as I before stated, and Herne in David's. They were our warm and sincere friends from the start, and, live as long as I may, I shall never forget them. When we went on deck, after our recovery from sea-sickness, I looked around me and scanned the entire horizon. Nothing but water was in sight; no land, no sail, not even the tiniest island to break the monotony of the view. Sea and sky comprised everything in the range of our vision. Our footing was somewhat unsteady, as there was quite a sea on, which had been raised by the steady wind which was then about due south. "We're at sea, sure enough," remarked David, "and what a pretty color the water is!" "You've not seen the prettiest of it yet by a long shot," said Haines; "wait till we get into blue water, where it's a mile or two to the bottom." "Isn't this blue water we're in now?" queried David. "No," was the reply, "we're not off soundings yet, though we probably shall be before the day is over. When we get off soundings we'll be in what the sailors call blue water; on soundings we call it green water. Look at the waves where they're breaking, and in the wake behind us, and you'll see that the water has a greenish color. Later on we won't see so much of that; the green will disappear and blue will take its place."