There are numerous navigational marks on the waterways to indicate channels and separation of traffic. It is important to be familiar with the basic marks to boat safely.


  • Some marks are warnings of speed limit and shoal areas.  


  • Red marks are on the right side of the channel heading from the sea inward


  • Green marks are on the left side. 


  • Red marks have even numbers while green ones have odd numbers. 


  • Some buoys have dual colors, and they are called preferred channel markers, with the top color indicating the preferred channel.


  • When near a shoal area, you must follow the day marks carefully to stay in deep water. Do NOT rely on electronic charts in these narrow channels.


  • In the Baltimore harbor, we have deep water except in a few zones near Ft McHenry etc.