“Could be,” Jerry said. “There are lots of old-time fishermen and other fine sailors who have absolutely no idea of how their boats work, and who wouldn’t know a law of physics or a principle of aerodynamics if it sat on their mastheads and yelled at them like a sea gull! They just do what comes naturally, and they know the way to handle a boat without worrying about what makes it run.”

Still heading on their downwind course, they passed several small islands and rocks, some marked with lights and towers, some with bells or floating buoys. They seemed to slide by gracefully as the little sloop left the mainland farther behind in its wake.

“Before we get out of the channel,” Jerry said, “I want to show you some of the channel markers and tell you about how to read them. They’re the road signs of the harbors, and if you know what they mean and what to do about them, you’ll never get in any trouble when it comes to finding your way in and out of a port.”

He pointed to a nearby marker that was shaped like a pointed rocket nose cone floating in the water. It was painted a bright red, and on its side in white was painted a large number 4.

“That’s called a nun buoy,” Jerry told Sandy. “Now look over there. Do you see that black buoy shaped just like an oversized tin can? That’s called a can buoy. The cans and the nuns mark the limits of the channel, and they tell you to steer between them. The rule is, when you’re leaving a harbor, to keep the red nun buoys on your port side. That’s the left side. When you’re entering a harbor, keep the red nun buoys on your starboard side. The best way to remember it is by the three R’s of offshore navigating: ‘Red Right Returning.’”

Sandy nodded. “I understand that all right,” he said. “But what are the numbers for?”

“The numbers are to tell you how far from the harbor you are,” Jerry said. “Red nun buoys are always even-numbered, and black cans are always odd-numbered. They run in regular sequence, and they start from the farthest buoy out from the shore. For example, we just sailed past red nun buoy number 4. That means that the next can we see will be marked number 3, and it will be followed by a number 2 nun and a number 1 can. After we pass the number 1 can, we’ll be completely out of the channel, and we’ll have open water to sail in.”

“Do they have the same kind of markers everywhere,” Sandy asked, “or do you have to learn them specially for each port that you sail in?”

“You’ll find the same marks in almost every place in the world,” Jerry said. “But you won’t have to worry about the world for a long while. The important thing is that the marking and buoyage system is the same exact standard for every port in the United States and Canada.”

“What’s that striped can I see floating over there?” Sandy asked, pointing.