Fog Piloting | Corinthians Annual Cruise 2025: Maine

Thoughts on Fog Piloting

Thoughts on Fog Piloting

Note: There is some rumor that Dick Woods ran the pen behind these comments.

Good Seamanship Practices in Fog
· Lay off courses well clear of all dangers
· Lay courses to marks with sounds
· Keep precise DR and current diagrams.
· Reset trip log at each fix.
· When plotting from doubtful positions, assume you are closer to danger than reckoning shows.
· Modern electronics are wonderful, but they have a habit of going haywire at the time they are most needed!
On hearing fog signals, note bearing and type of vessel:
Power
blast per 2 minutes
Sail

seconds each minute

•	1 long
•	1 long blast and 2 short per 2 minutes
•Anchored	Bell for 5
•To w i n g	1 long blast and 2 short per 2 minutes
•To w e d	1 long blast and 3 short per 2 minutes

Note: "long" = 4-6 seconds, "short" = 1 second
Answer every blast.
· If signal closes from ahead, bring to bear on port bow.
· If louder with no change in bearing, bring it on beam and go ahead on new course
· until is on quarter. Only then bring it on beam and keep it on beam by changing
· course until clear.
· If position relative land or danger prevents avoidance maneuvers, stop and give
· stop signal (2 long blasts per 2 minutes)
· If collision danger, show strobe, white flare, etc.

Fog Orders
· Skipper to deck
· Fix to chart
· Update DR track-current diagram
· Radar reflector up
· Running lights on
· Life jackets on
· Silence on deck.
· Listen.

Sound Fog Signals

Signal Heard	Type of Vessel
1 long blast every 2 minutes	power
1 long, 2 short every 2 minutes	sail
Bell every minute	anchor

SV Onward Comments on Fog Piloting

Contemporary yachts have digital chartplotter displays that can overlay enhanced digital radar returns on the navigation charts. This capability has substantially changed the art of fog piloting.
Good Seamanship Practices.
·      Get familiar with the operation of your radar and radar-chart overlay feature of your chartplotter.
·      As the chart is zoomed in for closer details, the radar may need to be adjusted (power reduced) so that details are not obscured by the strong returns from land masses nearby,
·      It is a good practice to be able to switch from radar-overlay mode to radar only (or view both with a split screen) as the radar-only display will make it easier to pick up the weaker returns from moving or stationary boats whose radar cross-section changes with its orientation.
·      Learn how to use the radar MARPA function to mark a return and track it relative to you.
·      Learn to follow transient returns – it is a skill to be honed. It could be noise. If it seems to appear in the same location – use the radar MARPA function to mark it and see if it is a vessel.
·      Under benign conditions practice navigating by chartplotter with radar overlay alone -- to mimic dense fog conditions.
·      Note: dense fog, rolly seas often go together near shore. Learn how your chartplotter display behaves under these conditions.   It can be very disorienting and almost impossible to navigate in dense fog when your display is jumping all over due to roll.
·      Be sure you have a fog horn and bell ready for use.
Onward as navigated extensively in conditions where visibility was limited to about 2 boat lengths. It take vigilance and practice with your equipment.

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Updated: 20 February 2025