Good morning and Happy New Year to you all!

The fog rolled in just a few minutes ago in Havre de Grace. It’s that pea soup stuff that seems to wipe out the whole world and from the office I can only hear the water…can’t see it.  I think we’re experiencing advection fog. That’s the type of fog that rolls in when a warm air mass tries to sandwich it’s way under a cold air mass. The warmer air gets cooled down to its dew point and forms microscopic drops of water, i.e. fog.  The Annapolis Book of Sailing says that advection fog doesn’t occur over land, so I’m pretty sure that’s it.  It is almost shirt sleeve weather out there. and I know it’s supposed to get colder very soon so that sounds like a recipe for advection fog.

I was out here over the weekend and saw a beautiful example of evaporation fog (also called steam fog).  I was looking out over the bay on what was a crisp clear morning, when, over the space of a few minutes, a dense fog appeared.  Evaporation fog occurs when cold, dry air moves over a warmer (and moist) mass of water or land. Some of the water evaporates into the cold dry air, temperature of the evaporated water drops to the dew point and voila… you’ve got fog!   Once things equalize the fog disappears, and so it was over the weekend… Within an hour or so everything was clear and crisp again!

The Coast Guard just radioed a fog advisory and that got me thinking about the proper signals when you get caught in the stuff.  I remember last October when I was bringing my sailboat down from Connecticut… I got caught in some dense early morning fog trying to get into Cape May on the Jersey shore.  Fortunately, I had RADAR and a recently updated chart plotter and was able to pick and choose my way into the harbor.  Once in the channel I knew I was supposed to make some noise at some interval, I just couldn’t remember the specifics.  Fortunately, before I left Connecticut, I had wired an electric car horn speaker to a switch in the cockpit, just in case, and my rare foresight paid off!  I don’t remember what pattern I was using…probably one long blast every couple of minutes, but inching my way through the Cape May channel I was met with the sound of another boat coming out… Fortunately I saw them on the RADAR screen and was able to get a visual on the ship… A Coast Guard Cutter… before it passed me to port.  I guess I was doing something right, because they just waved and went on by me!

What should I have done? Consulting the ABoS  again,  the proper sound signal for a sailboat that is under way in fog is one long blast, followed by two short blasts, sounded at least every two minutes. If you’ve turned on your engine (which is probably a good thing to do in the fog) you are now a power boat and should sound one long blast every two minutes. If your vessel is at anchor, the regs say one short, one long and one short, every two minutes; and if you’re aground in the fog (good times!), you can broadcast a danger signal to any boats approaching by sounding a short, short long blast, which is the horn signal for danger ahead.  There are several other sound signals out there, so consult your Regulations (COLREGS) to learn more., but committing these ones to memory will give you one less thing to worry about when you get caught in the stuff.

One more thing for you boat owners out there… Most newer VHF radios have automated horn signal functions. Of course, you need a speaker, but once you have everything wired up, it’s as simple as pushing a button (or tabbing through a couple of menus) to sound the signal appropriate for the conditions you’re experiencing.  I just recently installed one on my boat and am looking forward to putting it to the test in the upcoming sailing season!

Well, the fog morphed into rain a few minutes ago. Time to warm up the coffee.

Take care all. Fair winds and following seas!

Dan

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