As I awoke this morning on the first day of Spring, in almost zero visibility, it reminded me that Spring presents some additional challenges to the boating environment. As the water and air start to warm at different rates and the temperatures still can’t make up their mind if it is Spring or still Winter, there is a good possibility that fog will form. Fog is directly related to dew point. Dew point is that point at which the air at its current temperature can hold no more moisture. Remember that warmer air can hold more moisture that cooler air. If you lower the temperature of the air you reach the dew point and fog is created.
Fog is the primary cause of reduced visibility, but haze, heavy rain and snow all present problems for mariners. Boating in these conditions presents two hazards, navigational errors and collisions. The possibility of colliding with another boat, aids to navigation, or even land requires a strict lookout(s).
Preventing all of these dangers begins with reducing your speed. The old saying, “Be able to stop in half the distance of visibility” doesn’t appear in the Navigation Rules, but it is very good advice; remember slower is better!
A sailboat with an auxiliary engine, if under sail in fog, should have her engine available for immediate use, but you’ll be better able to listen for fog signals and other helpful sounds if you leave the engine off until it’s needed.
Fog signals must be sounded, the time interval in the Navigation Rules is the minimum required.
|Vessel||Required Sound Signal|
|Power-driven vessl making way||one prolonged blast every two minutes|
|Power-driven vessel not making way (stopped)||two prolonged blast every two minutes with a one second interval between them|
|Sailing Vessel, vessel not under command, vessel restricted in ability to maneuver, vessel constrained by draft, vessel engaged in fishing and a vessel towing or pushing another vessel.||one prolonged blast followed by two short blasts every two minutes|
Despite your best planning, you may be unable to avoid fog while boating. If you find yourself navigating in the fog, follow the guidelines below. If you find yourself in a life threatening situation, call the Coast Guard on VHF Channel 16.
- After everyone onboard has donned their PFDs, assign all people aboard to be a lookout. Maintaining a proper lookout is required by the Coast Guard Navigation Rules. All eyes and ears aboard should be looking for other boats, their wake, buoys and debris while listening for engines or other clues that signal another boat is near you.
- Slow down to a safe speed, if you can’t see the bow, that speed might be idle speed. The Coast Guard International and Inland Navigation Rules state that a vessel must proceed at a safe speed to avoid collision.
- Use a sound signal of some sort, which is required safety equipment by the U.S. Coast Guard, to signal your position every two minutes. You can use a bell, a loud hailer, a foghorn, or some other approved means for producing sound.
- Listen! Stop the motor periodically to listen to your surroundings. Sometimes in the fog, this may be your only way to avoid colliding with something. Listen for other boats, fog horns and other sounds from aids to navigation.
- Utilize your navigation equipment if you have it. Hopefully you have at minimum a GPS and a navigation chart to get your bearings. Preferrably, your boat will be outfitted with a RADAR so that you can see approaching objects.
- If you become disoriented, STOP! Do not keep going if you are unsure of your location, position and direction. Again, proper navigation gear will help you keep your bearings.