Common Non-Lateral Markers
Squares provide information such as places to find food, supplies, and repairs; and they give directions, distances, and other non-regulatory information.
Diamonds warn of dangers such as rocks, shoals, construction, dams, or stumps. Always proceed with caution and keep a safe distance. Never assume that every hazard will be marked by a buoy.
Circles indicate a controlled area such as “no wake”, “idle speed”, speed limit, or ski zone.
Crossed diamonds indicate areas off-limits to all boats such as swimming areas, dams, and spillways.