USCG Navigational Rules 101

USCG navigation rules are the equivalent of the rules of the road for mariners. The navigational system used on U.S. waterways was created by and is maintained by the Coast Guard.

Recreational boaters are encouraged to take a boating safety course to get a full understanding of the navigational rules and the aids to navigation (the “road signs” of the water). The USCG provides a small booklet, U.S. Aids to Navigation System: What You Need to Know about Markers on Water, for recreational boaters to use a quick reference guide.

The Basics of USCG Navigation Rules

While not comprehensive in scope, the USCG booklet touches on some of the most important topics and commonly asked questions about navigating on the water. “The Rules of the Road define the roles and responsibilities of vessel operators. If operators obeyed these rules, most accidents could be avoided,” the booklet prefaces.

The first three rules covered in the booklet help reduce the risk of collision:

• Lookout – each vessel should have a designated person as a lookout (for hazards, other vessels, objects, weather) at all times.

• Speed – vessel operators are responsible for using their best judgment as to what constitutes a safe speed. They must take visibility, traffic, weather, and their boat’s maneuvering ability into consideration and proceed with caution.

• Giving way – when nearing another vessel, vessel operators are expected to understand when to give way (yield) and when to stand on (maintain course and speed). A few examples of right of way navigation rules are covered in the next section.

Navigational Rules for Passing Other Vessels

How to properly pass or overtake another vessel is one of the key areas of discussion in the navigation rules of the road.

Here are three common situations vessel owners should fully understand how to handle:

• Overtaking – when you want to pass another boat traveling in the same direction, you may pass on either side, provided you give adequate sounding alarms. If you want to pass portside, you sound your horn twice, and await the other vessel to respond in kind. To pass starboard, sound once and await the other vessel to respond in kind.

• Port to port passing – if you’re coming head-on with another vessel, port to port passing is preferred. Sound your horn once to make your intent clear. The other vessel should respond in kind.

• Starboard to starboard passing – starboard passing in a head-on situation is allowed when necessary. To signal your intent, sound your horn twice. Again, the other vessel should respond in kind.

Get a Better Understanding of the Rules of the Road

There are several guides available online and on the market for understanding the nautical rules of the road. Take the time to become familiar with all the rules by which you’re expected to abide for your and your passengers’ safety, as well as the safety of others on the water.

The complete version of the navigational rules is detailed in the USCG instruction manual, BK-299 U.S. Coast Guard Navigation Rules, International & Inland (USCG COMDTINST M16672.2D). You can also stay current on topics of interest to boaters by perusing the Marine Education Textbooks blog, which is updated regularly with interesting articles pertaining to the maritime industry.