Lateral buoys indicate safe routes by marking the left and right sides of the deepest water. There are two main
types of lateral buoys: port-hand buoys and starboard-hand buoys.
 
Port-hand buoys:
- Are used to mark a danger or the left-hand side of a channel (when facing upstream);
 - Should always be kept on the port side of the vessel when traveling upstream;
 - May have a single green cylinder shaped topmark;
 - May have a light that is green in colour;
 - Are flat on top, if they do not carry a light; and
 - Are identified by letters and odd-digit numbers.
 

Starboard-hand buoys:
- Are used to mark a danger or the right-hand side of a channel (when facing upstream);
 - Should always be kept on the starboard side of the vessel when traveling upstream;
 - May have a single single red cone shaped topmark pointing upward;
 - May have a light that is red in colour;
 - Have a pointed top, if they do not carry a light; and
 - Are identified by letters and even-digit numbers.
 
REMEMBER: The upstream direction is the direction taken by a vessel when proceeding from seaward, toward the headwater of a river, into a harbor or with the flood tide. In lakes and rivers where this is difficult to determine, the use of cardinal buoys are preferred.