What color and shape are cylindrical buoys that mark the left edge of the channel when heading upstream?

Cylindrical buoys that mark the left edge of the channel when heading upstream are indeed green in color and take on a cylindrical shape. This is part of the U.S. aids to navigation system, which utilizes specific colors and shapes to convey information to boaters. The green cylindrical buoy designates the port side of the channel as you travel upstream, essentially guiding vessels safely within navigable waters.

Understanding the color and shape coding of navigation buoys is crucial for safe boating. The left-hand side of a channel is marked with green buoys, which helps boaters orient themselves as they navigate towards less familiar waters. This buoy system works in conjunction with the red buoys marking the right side of the channel, which are conical in shape, creating a standardized method for identifying channel markers regardless of the location.