Inland Navigation Rules
Nav Rules Make Easy
Rule 19
In the Nav Rules Made Easy series, we’ll explain each Inland Navigation Rule, with an emphasis on the information that’s most important for recreational sailing in the San Francisco Bay. We won’t include portions of the rules that are highly technical and intended for commercial mariners.
Note: If you travel more than one mile outside the Golden Gate Bridge or if you charter a boat in another country, the International Rules apply. Many of the International Rules are exactly the same as the Inland Rules. However, there are also a few that contain important and significant differences from Inland. Make sure that you study and learn International Rules if you are traveling in international waters.
This is just a simplified summary of the rules. To get detailed information, please refer to the Navigation Rules and Regulations Handbook from Department of Homeland Security, United States Coast Guard.
Rule 19 – Conduct of vessels in restricted visibility
Rule 19 applies when there is restricted visibility and vessels cannot see each other. Fog and heavy rain are the most frequent causes of restricted visibility.
All vessels must be operating at a safe speed and the helmsperson must be ready to maneuver the boat quickly. A boat is traveling at safe speed when the boat is able to safely stop in adequate time to avoid a collision.
Rule 19 reminds us that in restricted visibility, we must follow rules 5 to 10 which apply all the time:
- Rule 5: Maintain a lookout
- Rule 6: Operate the boat at a safe speed
- Rule 7: Be aware of all other boats and objects on the water. If any possibility of collision exists, assume there is risk. Use all equipment available (radar, binoculars) to figure out if there is risk of collision.
- Rule 8: Avoid collisions. When your boat is the “give-way” vessel, make a large enough course change to clearly communicate to the other boat that you are changing course. Make your course change sooner, rather than later. Give the other boat plenty of room. In close quarters where a course change is not possible, slow down … go to neutral or even reverse to avoid any possibility of a collision. Make sure that you maintain “rudder authority” – the ability to steer the boat. Don’t go so slow that you can’t steer!
- Rule 9: Understand the definition of “narrow channel”. Know when you are in a narrow channel. When you are in a narrow channel, stay as far to the starboard side as possible. Do not get in the way of vessels that can only operate in the channel. Give way to barges, tugs, car carriers, cargo ships, and tankers.
- Rule 10: Understand that Traffic Separation Schemes exist and contain lanes for traffic going in one direction or another. The schemes include an area between traffic lanes that acts like a median on the freeway – the “separation zone” keeps apart traffic going in opposite directions.
Know when you are in a Traffic Separation Scheme. When you are, go with the flow of traffic. Stay out of the Separation Zone. Merge into traffic in traffic lanes with as little angle as possible to the direction of travel. Cross traffic lanes at a 90 degree angle.
If you are using radar and see another vessel on the radar screen, decide if there is any risk of collision. If there is risk of collision, take action as soon as possible to alter course.
If the other vessel is detected forward of your beam, do not alter your course to port.
No matter where the other vessel is detected, do not alter course toward the other boat.
If you hear a fog signal from another vessel forward of your beam, reduce your speed to “bare steerageway”. Continue navigating with great caution until any risk of collision is gone.
