When proceeding upstream, where should a red lateral marker be kept?

A red lateral marker is used to indicate navigation channels and assists in determining the safe passage for vessels. When proceeding upstream, the convention is to keep the red marker on the right side of the vessel. This is in accordance with the "Red Right Returning" rule, which means that when you're returning from sea to the shore (or in the case of moving upstream on a river, which is analogous to a return to a more sheltered or landward area), the red markers should remain on your right side.

This rule helps in maintaining consistency for navigators and contributes to safer boating practices, as it allows boaters to understand which side to keep markers on, reducing the risk of collisions or running aground. By keeping the red marker on the right side when navigating upstream, you ensure that you are following standard boating navigation practices.