Transcript for Waterway With Buoys and Markers
U.S. Aids to Navigation System (ATON)
From an overhead view, boats travel up waterways, passing buoys and markers of different types.
- Safe Water Markers
- These are white with red vertical stripes and indicate unobstructed water on all sides. They mark mid-channels or fairways and may be passed on either side.
- Green Colors, Green Lights, and Odd Numbers
- These mark the edge of the channel on your port (left) side as you enter from the open sea or head upstream. Numbers will usually increase consecutively as you return from the open sea or head upstream.
- Red Colors, Red Lights, and Even Numbers
- These mark the edge of the channel on your starboard (right) side as you enter from the open sea or head upstream. Numbers will usually increase consecutively as you return from the open sea or head upstream.
- Can Buoys
- These cylindrical-shaped buoys are always marked with green markings and odd numbers. They mark the edge of the channel on a boater’s port (left) side when entering from the open sea or heading upstream.
- Nun Buoys
- These cone-shaped buoys are always marked with red markings and even numbers. They mark the edge of the channel on a boater’s starboard (right) side when entering from the open sea or heading upstream.
- Red and Green Colors and/or Lights
- These are placed at the junction of two channels to indicate the preferred (primary) channel when a channel splits. If green is on top, the preferred channel is to the right. If red is on top, the preferred channel is to the left. These are also sometimes referred to as “junction buoys.”
- Controlled Area
- Circles indicate a controlled area such as no wake, idle speed, speed limit, or ski zone.
- Danger Area
- Diamonds warn of dangers such as rocks, shoals, construction, dams, or stumps. Always proceed with caution. Never assume every hazard will be marked with a buoy.
- Exclusion Area
- Crossed diamonds indicate areas off-limits to all vessels such as swimming areas, dams, and spillways.
- Mooring Buoys
- These are white with a blue horizontal band. They are usually placed in marinas and other areas where vessels are allowed to anchor. These are the only buoys you may legally tie up to.
- Inland Waters Obstruction Markers
- These are white with black vertical stripes and indicate an obstruction to navigation. You should not pass between these buoys and the shore.
- These are permanently placed signs attached to structures such as posts in the water. Common daymarks are red triangles (equivalent to nuns) and green squares (equivalent to cans). These may also be lighted. Channels that are part of the Intracoastal Waterway (ICW) are identified by yellow symbols on channel buoys and markers.