Fog Warnings

During the Continuous Marine Broadcast (on weather channel 1, on channel 21B, or by calling 250-339-0748), you can often hear the reminder: "'Fog' implies visibility of less than one mile." So when the subsequent forecast for "Straight of Georgia, North of Nanaimo" includes a comment to expect fog, be ready for conditions of reduced visibility.

Of course, just hearing a warning of possible fog in the weather broadcast does not mean that fog will be present (after all it is a forecast). But it is a valuable warning that you should be watching for reduced visibility. Weather forecasts may also include warnings of similar conditions, e.g., smoke during wildfire season. 

Anticipation of Various Visual Ranges

The range from the marina breakwater to the Dolphin, to HMCS Quadra, or to Goose Spit light is a bit over half a mile. And the range to the Royston shoreline is a bit more than one mile. All of these landmarks have lights that are shining even in the middle of the night. 

Use these landmarks to get an idea of what the visual range is as you exit from the marina: if you can see the Royston lights, visibility should not be an issue. However, if you cannot see the Royston lights, but you can see the other lights, the visual range should be between one half mile and one mile -- not great, but a situation in which we can operate if we take care.

If the lights on Goose Spit, on the Dolphin, or on the wharves at HMCS Quadra cannot be seen when exiting the breakwater, visibility is very restricted... probably less than a half mile. This would be a situation with very restricted visibility, and great care is required.

It does not mean we should not operate, especially if we are on a SAR mission. However, the GAR should be assessed accordingly. If the GAR is high, we may have to consider mitigation of risk. And if we cannot mitigate the risk, we may have to consider cancelling our participation in the mission.  

A Benchmark for Acceptable Visual Ranges

A benchmark visual distance that many deep-water mariners have used to assess when they are in restricted visibility is based on the range at which their own sidelights and masthead lights should be visible to other vessels. 

For large commercial vessels, Rule 22 requires that masthead lights be visible at a range of six miles and sidelights and other lights at a range of three miles. Thus, when conditions are such that a master or crew know that their own lights will not be visible at these ranges, conditions are getting dicey — other vessels will not be able to react as they should if the lights were giving appropriate warning at the distance required by Rule 22. 

For our vessels, which are under 12 metres in length, the masthead light and sternlight should be visible at a range of two miles and the sidelights at a range of one mile, by Rule 22. If you think that conditions are such that other vessels will not detect your own vessel at these ranges (and respond accordingly), you should anticipate that rules for restricted visibility might apply.   

Last modified: Saturday, 10 January 2026, 1:49 PM