Boating sign definitions
Alpha Flag, International Diver Down
The blue Alpha Flag is required by federal law to be displayed by vessels engaged in diving operations. With either flag, boaters should exercise caution.
Diver Down
The red Divers Flag is not an official flag but is used widely by recreational divers.
Boats Keep Out
Nature of danger may be placed outside crossed diamond (e.g. waterfalls, swim areas, rapids).
Caution
Controlled Area as indicated in circle (e.g. speed limit, no fishing, no anchoring, ski only, slow, no wake, no ski, no prop boats).
Channel Marker Left
Lateral System. Keep buoy on left facing upstream.
Channel Marker Right
Lateral System. Keep buoy on right facing upstream.
Danger
Nature of danger may be indicated inside the diamond shape (e.g. rocks, reefs, dams, construction, snags).
Destruction
Cardinal Buoyage Marking System. Do not pass between shore and buoy.
Information
Tells direction and distances to locations, food, repairs, supplies and other non-regulatory messages.
Mooring Buoy
White with reflectorized blue band. May have white light or reflector.
Visual Distress Daytime Signal