Top Menu

It’s foggy. So foggy in fact that you can’t see more than 50m in front of your boat. For whatever reason, you NEED to get into a harbor, as opposed to staying out in safe water while you wait for the fog to dissipate. What do you do? Well, the first thing you don’t do is ask me to take the ship into the harbor, because of all the things I did on my recent Yachtmaster exams, I think I did the most poorly on the blind pilotage exercises.

If you did find yourself in the situation above, the basic strategy (sans functioning chartplotter) would be to plot a course to one side or the other of the harbor, as opposed to directly at it. Once you reach a certain pre-selected depth of water, you should be able to follow the depth contour as shown on the charts to slowly but safely navigate your way in. As an example, once you reach 10m of water, make course corrections so that the depth of water under the boat stays about the same as you move in the direction of the harbor. Sounds simple, right?

When we did this during our course, and then later on the exam, the person being tested was down below with only a paper chart to guide them. He would call up courses to steer to the helmsman while in return, the helmsman would call back depth information to the navigator. As you can imagine, there is a bit of a time delay that occurs during this process. Of course, during the prep and exam, this all happened in broad daylight with good visibility but to the person down below, that didn’t mean anything because he was essentially blind to what was going on up on deck.

As I said, I need a bit more practice on this. I do think it would be significantly easier to do from the helm and with a chartplotter right in front of you but with that said, I do hope to avoid any situations where I will be forced to put this particular skill into practice.

This is where we practiced this skill, the entrance to the St. George’s harbor.

Just for fun, I typed out all the sound signals that we were required to learn with the ones further down the list relating to restricted visibility situations (fog) as described above (legend at bottom).

  • _ I am altering course to starboard
  • _ _ I am altering course to port
  • _ _ _ I am operating with astern propulsion
  • _ _ _ _ _ Your intensions are unclear / I do not think you are taking enough evasion action
  • ______ ______ _ I wish to pass you on your starboard side
  • ______ ______ _ _ I wish to pass you on your port side
  • ______ _ ______ _ I agree with your intention to pass me

Restricted visibility (sounded at 2 minute intervals)

  • ______ Power boat underway
  • ______ ______ Power boat underway but stopped
  • ______ _ _ The following boats underway: Sail boat, vessel not under command, vessel restricted in it’s ability to maneuver, vessel constrained by draft, fishing vessels
  • ______ _ _ _ Sound signal given by vessel being towed, if it is manned (following the towing vessels signal ______ _ _ ),
  • ______ _ _ _ _ Pilot boat underway
  • ______ ______ _ _ _ _ Pilot boat underway but stopped

Anchored/aground (sounded at 1 minute intervals)

  • bbbbb  -Vessel under 100m at anchor
  • bbbbb ggggg – Vessel over 100m at anchor (gong sounded in aft of vessel)
  • _ ______ _ – Vessel at anchor warning signal
  • B B B bbbbb B B B – Vessel under 100m aground
  • B B B bbbbb B B B ggggg – Vessel over 100m aground


  • _ Short blast on horn/whistle – 1 second in length
  • ______ Long blast on horn whistle – 4-6 seconds in length
  • bbbbb Rapid ringing of bell – 5 seconds
  • B Distinct stroke on the ship’s bell
  • ggggg Rapid ringing of gong – 5 seconds

Public Service Announcement 🙂 Stop right here! Please click this link to vote for our buddy Carlton Grooms in the Tommy Bahama Rumologist contest before continuing. You have until Monday October 10th at 9:00 p.m. PST to let TB know who should be the very first rum ambassador.


  1. Sounds like a fun test exercise. I’m not sure how real it is. I started sailing before GPS and didn’t have Loran. I got out in heavy spring fog a few times.

    * A precise DR plot never let me down. But it had to be text book, with allowance for set and leeway. Once I nearly rammed a channel marker in 20-foot visibility conditions after a 5 mile run. I wasn’t expecting the marker to be right in front of us!

    * In most areas I sail, the water is too shallow and too variable to believe the charts. Many coastal US waters are sand and the contours change with passing storms. Trying that on the eastern shore of Virginia would be plain silly if it wasn’t plotted since the last storm.

    I would never choose to approach a jettied entrance that way if the viability were under a few hundred feet. I need room to turn around if I’m wrong. Once I anchored for 2 hours, since there really wasn’t enough visibility to safely head in or out (the fog had quickly approached from shore). Sometimes, if you’re lost in the woods, the best thing to do is sit down! We modern folk aren’t used to being told to wait for the weather, but sailors learn.

    • It did not seem like a “fun” exercise at the time.

    • Drew,

      I’m right there with ya. Around where we are you can’t trust the charts hardly at all. Hurricanes constantly blow the shoals around and recently the Army Corps opened a major flood gate for the Mississippi so of course it dumped tons of mud everywhere in new spots. Just can’t trust a chart *that* much. It’d be nice to be someplace where you can actually have some faith in the depth soundings.

      As a side note. In fog, my biggest fear is some power boater hauling ass and not able to hear the sound signals. I’ve seen them doing that in the ICW.


      • I do hear you Tate and I agree but remembering that I said waiting in safe water is NOT an alternative and you HAVE TO go in, what better method would there be? You have to start somewhere.

        • Mike,

          In a situation such as that, I’d honestly trust GPS more than local charts. I’m not saying that is right in all places, but locally I certainly would, even if I knew it was 100s of feet off.

          AIS can be helpful for finding a channel around my parts too since all the big boats have them and commercial shipping is very high around here. You can almost always see one of the big tankers or tugs around and they know where they’re at generally.

          In a real pinch you can also call for Coastie or anyone with radar to help guide you in via their ability to “see”.

          If it were an absolute last resort I might try nav by depth, but in the marsh lands you’re really tempting fate. I’d put 3:1 odds against any skipper using only a chart for depth knowledge trying to go in blind. Odds are you’d run aground either because of shoaling or because you calculated your course wrong since depths didn’t match where they should.

          I understand the importance of your test and exercise and all that, but like they say, skills don’t always apply universally. That test seems more like a test of a skill to have in non-marsh areas. In our cruising home I’d def try everything I mentioned first, and if others have suggestions on “out of the box” ways to try it I’d love to hear them too.

          Ps. Congrats on passing!


  2. Hi guys

    You should google Crane falls over at Collins Bay Marina .

  3. We are good , hauled last week at Loyalist Cove . Had a great summer , mostly with Pirate Jenny . Still may need a capitain to bring Night Shift south next year . Interested ?????

  4. Bummer about the crane incident. We had heard Hub and Mich sold the marina? Not agreat way for the new owners to start out, OUCH.

  5. Sounds like an interesting thing to keep practicing. I’ve heard the 100m contour is a safer one to follow, thus mostly avoiding the shifting sands of time! 🙂

  6. Just for your reader’s information – there is a different set of sound signals for International waters (as in your case) and sound signals for inland. (God and bureaucrats only know why!)

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

This site uses Akismet to reduce spam. Learn how your comment data is processed.