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The blinding, paralyzing blanket of dense fog

The shrieks and groans of steel crashing and grinding into steel came from all directions out of the impenetrable fog. Huge unseen engines roared like prehistoric beasts as two tugs moved gigantic mud barges. They had to disconnect their tows, rush around to the sterns of the barges and grind into them to push and pull. And nobody could see.

Boats should move slowly in fog. Navigation Rules require vessels to reduce their speed to as low a level as is prudent under the circumstances.

We were heading up the Cape Fear River in North Carolina. Shortly after we’d left the ICW and headed into the river, we heard the captain of a large ferry broadcast a securité on VHF channels 13 and 16. Then came the dreaded words: They were proceeding slowly in fog with “limited visibility.”

As we discussed turning around to gain the shelter of a marina, the gray bank from upriver engulfed us. It seemed soft, moist and gentle, but it was deadly. The world disappeared, as had a gigantic dredge, two large tugs, mud barges and a crew boat speeding to the dredge. We knew where they had been, but we couldn’t be sure where they were going.

In the invisible world around us, we could hear the commercial captains talking on VHF 13, asking one another where they were, where they were bound and what they could see. Voices from another world — all tense, tight and worried. I hailed the crew boat on 13, thinking he was heading in my direction. I told him where I was, near a large red nun, finishing with “I hope you can see me when you get here.” He laughed nervously. “Well if I do, we’ll sure be close.”

The Cape Fear River up to Wilmington serves container ships and freighters from around the world. The channel is deep. Outside the channel, mud flats — many bare at low water — lie in wait, in some areas studded with old pilings and other remnants of past times. The tide at times runs 2 knots or more.

We knew there was a range tower well out of the channel and we had it on radar. The water was shallow there, but deep enough for us if we were careful to stay away from the shoreward side, where water was only a few feet deep. Better to go aground than get caught between gigantic steel hulks gnashing away at each other. The large boats wouldn’t be able to come up in the shallower water … we hoped. We found the range tower and began holding place. Waiting. Hoping the stuff would lift.

Dozens of other pleasure boats, from 30-footers to an 80-foot yacht, also were heading upriver. In a short span of time they also had plowed into the fog. Some continued on; some stopped, milling about. You could hear them; you couldn’t see them. Radar showed the targets; some were great blobs. These we knew to be the dredge and the tugs and barges. Some were smaller — the yachts. Some you just couldn’t tell. Were they buoys? Pilings? Small boats?

Be particularly careful around large commercial traffic, in this case a tug with a barge and dredge equipment in the Cape Fear River.

Every so often a small open boat would suddenly appear only yards away like a missile hurtling out of the fog, its outboard roaring, and then disappear. These boats were around 18 to 25 feet, with happy fishermen looking forward to hooking something offshore. I don’t know how they got that far and why we never heard any distress calls from them. I guess they knew a lot more than the rest of us — or maybe they just had the luck of the clueless.

Unfortunately, there are many boaters who don’t have a clue. I’ll never forget a Sunday afternoon when we were in fog between Block Island, R.I., and Narragansett Bay. We were creeping along in zero visibility, intently peering at the radar and listening. Suddenly we saw a target rapidly closing. Then we heard roaring engines. A low-flying plane? No, a high-flying weekender out in a fast planing cruiser, speeding home on autopilot, apparently confident his radar would tell him if anything was ahead.

Several other fools passed us in the next few hours, very close in, obviously unaware of our presence. I mentioned it to a commercial fisherman in Newport. “Yeah, we see it all the time. These people are killers,” he said.

We were using radar and a GPS/chart plotter that day in the Cape Fear River. They helped, but there’s nothing like seeing. When you can’t see, you rely more on listening, but fog plays tricks with sound. We couldn’t tell for sure what direction the clanging and screeching of metal was coming from. We heard the deep-throated rumble of the engine of what must have been a very large vessel, but we didn’t know where it was prowling.

We anchored with several other boats, including that 80-footer. Finally, the shores of the river began to emerge, the fog dissolving in the sunlight. We were on our way into what remained of a beautiful cruising day.

No matter how hard you try to avoid it, fog will find you if you’re on the water enough. It often comes unannounced. Sometimes we know it’s coming, but there’s little we can do to avoid it. It may be an eerie cloud bank rolling in from the sea, lasting for days. Or it can rise in the morning from the still inland waters, quickly killing your vision, only to burn off a few hours later.

In addition to paying close attention to the forecasts and our own weather intuitions, we’ve found that standing by on VHF channels 16 and 13 is a good way to get a warning of fog ahead. We hear other vessels talking about it.

What follows are some things we’ve found helpful through the years. Other tactics and actions might be more helpful in your situation. Each skipper has to do what’s best under the circumstances. And I’m not suggesting that what works for us will work for you on your boat under your circumstances. You’ll have to make your own calls, and maybe on some foggy day when you pass me sitting on a mud bank, you can tell me what I should have done.

Fog psychology

Fog at sea can bring disorientation, panic and danger. Even with all the electronic eyes and ears of modern vessels, it commands respect and fear. It’s a double whammy: We have to be sure we don’t hit something and we have to be sure that “something” doesn’t hit us.

It’s important to understand when you’re going into fog that the world is suddenly going to change dramatically, as are the ways you’re accustomed to dealing with it. Basic instincts aren’t going to work well, if at all. Your normal ways of sensing what’s around you are going to be virtually useless. You’re likely to become confused and disoriented. Mentally prepare for this and take immediate steps to cope with the situation.

When we suspect fog is coming, we immediately turn on all relevant navigational instruments and note our compass course. Some hardware, such as radar, has a warm-up time, sometimes up to 3 minutes. Even a short time can seem like eternity if you can’t see and there’s danger nearby. We turn on our running lights, verify that the horn is working and get out spotlights — sometimes they may attract attention, but be careful not to impair anyone’s ability to see — and safety gear.

While we can still see we also verify our position and the proximity and bearing of any possible dangers, such as boats, reef, shoals and aids to navigation. To do this, we use the chart plotter, radar and paper charts, as well as visual and compass bearings. We then form a plan. A plan at sea might have to be ditched for a better one, but it helps to go into the situation with something in mind.

If we’re in restricted waters, we stop if prudent (more on this later). If we’re in open water, with no known hazards, we usually proceed, slowing to a speed suitable for the circumstances, which usually means moving just enough to maintain steerage and control. (The Navigation Rules, International and Inland, require vessels to decrease speed to as slow as is prudent under the circumstances. Learn the rules now if you’re not familiar with them.) The faster you’re running, the quicker you must react to danger. In fog, danger often comes with little advance warning. We also begin sound signals, as required by the rules.

It's important to understand when you're going into fog that the world is suddenly going to change dramatically, as are the ways you're accustomed to dealing with it.

We program our plotter with appropriate waypoints and/or routes if we haven’t already done so. If we don’t have time to do this, we’ll pick out a safe target and put in a “go to” route.

The watch

We set up extra watch in fog. This means having everyone who is available up on deck and assigned a watch task, but usually only my wife, Mel, and I are aboard. One of us is at the wheel, watching to the extent that it’s possible, but often visibility is limited to just a few feet. The person at the wheel is also concentrating on radar and plotter information, perhaps the depth finder, and monitoring radio broadcasts.

If a response to a radio broadcast is appropriate, the helmsman usually will do that: “Yes, I’m the target approximately a quarter-mile to the east of Red 14 in the Indian River, proceeding at 3 knots on a course of 180 degrees, and I do have you on my radar.”

The person on watch frequently stands outside the steering station, looking into the fog and listening. It’s best for the lookout to be at or near the bow. You can see things quicker and there is less hindrance from your engine noise. If there are enough crewmembers, a lookout on the stern is also helpful, watching for overtaking vessels and as a double-check on the bow lookout. The helmsman should be prepared to slow engines to dead idle and stop if the deck lookout thinks he detects something.

The lookout is outside because visibility, such as it is, will probably be better without the misting of the windshield or wind screen caused by fog. In dense fog, you sometimes can’t even see your own bow. And the swirling mist makes phantom shapes that are confusing and tricky. Occasionally, as you become accustomed to fog, you’ll begin to pick out temporary lighter spots or density changes that indicate a target.

The outside watchman has a good set of binoculars ready, but might not use them unless they’re really needed to help clarify an anomaly. They quickly mist up in fog and require constant wiping with a soft cotton cloth. When you do peer into the fog with binoculars, be prepared to see anything from nothing to shapes that are very different from what you see with your eyes. This can be confusing or helpful. Also, look for other clues. For example, waves can indicate that a boat has recently passed.

It’s also easier to hear while outside. Any unusual sound should be considered suspect and should be checked out. In fog, the slightest noise from your boat can distort or drown out the slightest noise from another boat. Sometimes it helps to kill the engine to better hear. I’m normally reluctant to do this because we never know when we might need to quickly get out of the way of something and our dead idle produces very little noise, but circumstances might call for this.

Fog not only muffles sounds, but it also plays tricks with them. It’s often difficult to know the direction of a sound, but if you hear something, try to get a general idea of the direction, alert the helmsman and use radar and/or the plotter and charts to hopefully sort it out. Sound your horn. You may also need to call out on the VHF. Sounds you might hear include fog signals from other vessels, engines, tidal rips, breaking waves, wakes, land sounds such as sirens or traffic, signals on aids to navigation (ATONs) and even people talking. (This really makes your day.)

The on-deck watch should also be sensitive to smells. We’ve smelled land, rocks, other boats (from their exhaust or moldy hulls), commercial fishing boats, ATONs and even tidal changes. Smells, like everything else, are muted by fog but sometimes provide important clues.

Obviously, anyone on deck should wear the proper life jacket with strobe, whistle, personal locator beacon and any other appropriate safety equipment.

Help at the helm

A blanket of fog moves quickly into open water, ready to engulf this boat and channel marker.

I’ve found that the combination of trying to steer in dense fog, trying to keep up with chart plotter displays and trying to figure out the movement of radar targets can be quite an overload, particularly when there are a lot of issues. It can be very helpful to have another person near the helm to help the helmsman.

Steering to a radar screen, plotter or computer screen, or even steering to a compass when you can’t see, is extremely difficult unless you’re experienced at it. Try it out sometime to understand how difficult it can be and to get the feel of it. This will help prepare you for the emotional jolt when you’re behind the wheel in the soup and help you develop skills in dealing with the situation.

In good weather and open water, with at least one other competent person aboard to keep watch for other boats and dangers, force yourself to steer toward and away from a radar image without looking at anything but the radar. Do the same for a target on a chart plotter, or the combined screen overlay, if that’s what you have. If your target is a far distance off, this might not be a problem, but if it’s at close range, it can be very difficult. If the target is moving, it’ll be more difficult. If there are other targets around, it’s even more difficult. The reasons for this include the fact that we are accustomed to constantly verifying what we’re doing by sight. We aren’t used to steering “blind.” This can easily add an element of panic.

Another problem is that radars and chart plotters don’t have an instant real-time acquisition and refresh rate. You can pay more money and get better rates, but it still isn’t going to be as close to real time as it is when you see that ATON or ship with your eyes. Complicating the situation is the fact that you’ll probably be moving much slower in the water than usual; therefore, your boat will respond to rudder more sluggishly.

As you try to compensate for a new image on the screen that has suddenly jumped off to the side, your boat isn’t going to react the way you expect when you turn the wheel, causing a tendency to overshoot and undershoot. When targets are close in, and especially when they’re moving, this can be an extremely serious problem.

I can steer best if I quickly look at the compass when I’m concerned about a target on the radar or a bearing on the plotter. This gives me a compass bearing on a traditional compass. This method works for me because I’ve been steering compass courses for almost 60 years. Other tactics might work better for you. Practice can help you determine what suits you best. While practicing, learn how to use and interpret the displays on your electronics intuitively. You won’t have time to figure it all out when you’re fogged in.

Also, practice can help you become proficient with radar. You’ll find it’s hardly the panacea many think it is. It doesn’t necessarily show you what’s out there. It can miss some targets completely, especially if it isn’t adjusted correctly for the circumstances (rain, sea clutter, mist, etc.). Some radars “automatically” adjust to certain variables, but you should never rely on this function completely.

Learn to distinguish targets. A blob looks like a blob, but a big steel ship will generally create a much larger blob than a buoy — unless perhaps the buoy has a well-designed radar reflector. You might find that your radar won’t pick up a small wooden boat or a set of old wooden pilings protruding into the channel. Disappearing and reappearing blobs are common. Sometimes it’s because of a wave or echo or some other anomaly. Sometimes it’s because of a small boat or obstruction. We’ve even picked up a flock of geese in V formation and, once, a single pelican — and this when the set was properly tuned.

Become familiar with how your set reacts to different phenomena. Your boat can create radar reflections, particularly if it’s mounted with a mast or other structure behind it; you’ll need to recognize that. Play with your radar every chance you get to learn how to adjust it so that it reads well in various environments and so you know what it’s telling you.

It’s critical to learn how to determine whether a target you see on radar is closing with you. This may be a no-brainer when you’re also using your eyes with good visibility, but in the fog (or at night) it can be quite difficult unless you understand radar and how to use it, including collision prediction. Depending on your boat’s characteristics, you may want to have a radar reflector up. The subject of radar use can fill books — for example, see “Radar for Mariners” by David Burch, published by International Marine.

Reach out

Morning mist rising from warm water on a cold day can quickly blanket a narrow waterway.

Not only do you want to know what’s out there, you also want all other boats to know you’re there and where you’re going. The Rules of the Road call for specific fog signals, and these should be used from the outset, but pause occasionally to be sure your signal isn’t drowning out another.

Sound signals can’t be relied on exclusively to get you through. They might not be heard in an enclosed wheelhouse with engine noise in the background. And, as noted above, it may be difficult to determine the direction of their source in the fog. All of these are additional reasons for posting lookouts on deck, preferably in locations where they can hear and see as well as possible.

It’s also be helpful to call out a brief securité on the VHF radio, giving your position, course, vessel name and type. But if there are many boats around you it may become counterproductive if everyone is calling. Use your best judgment as to when to transmit. Always listen for other calls and respond if prudent.

When you give your position it may be appropriate to give not only your lat/long but also your position relative to a known ATON or landmark. For example, it helps to give your position as “a half-mile north of lighted Green 57 at the entrance to XYZ River.” Many skippers are so busy in fog that by the time they determine the location of a lat/long position it might be too late.

Some commercial vessels and large yachts with sophisticated equipment can tell quickly what your lat/long means to them and will probably know where you are and your speed and bearing. But you won’t know whether the other vessel is so equipped. Obviously, properly set up AIS can be very helpful.

There is sometimes a question about the best VHF frequency to use. The Federal Communications Commission confused the issue some time ago, in my opinion, by asking pleasure boats to use channel 9 for calling in order to relieve congestion on 16, rather than actively prosecuting the people abusing 16. Channel 16 is the hailing and distress channel. Most commercial traffic monitors that frequency. Channel 13 is the bridge-to-bridge frequency and most commercial traffic also stands by there. This is important to know when you’re in fog.

When we call out a safety securité, we call on 16 and also on 13 because I believe these are the most relevant channels. We also monitor both frequencies. Monitoring 13 often gives insight into what’s going on because you can hear commercial traffic talking about what they’re doing to handle the situation. We don’t rely on scanners for monitoring multiple VHF channels because these sometimes miss all or parts of transmissions. Instead, we have two VHF sets at the helm. We state our frequency when we call out a securité so that a responding vessel knows which frequency to use. If you stand by on VHF 9 to the exclusion of the other two, you may miss important transmissions.

Channel 13 transmits only on 1 watt, by default, on most sets, but better sets have a temporary manual override, which may be necessary under some circumstances. If your second VHF is a handheld, it will not transmit as far because of its lower power output and antenna. Obviously, as the number of boats increases in an area of fog, the complexity of sorting out all the VHF transmissions and other signals increases.

Nobody move

Often a good tactic when you’re in inland waters is to stop moving, but first consider the safety issues. You wouldn’t want to anchor in a navigation channel or stop without notice and agreement while being overtaken. But there’s often a place to pull out of the channel and drop the hook when caught in fog in rivers or other inland waters. This is a time when your plotter and depth finder can be very helpful.

However, anchoring just to the side of the channel might not be as safe as you think because other boats can be confused and traveling outside the channel for a time. It’s not unusual for shallower-draft vessels to deliberately proceed outside the channel during fog in order to avoid larger vessels. We usually prefer to anchor with a fleet of boats (if there’s room to safely do so), positioned well out of the channel. With many boats clustered, we know there’s probably a more conspicuous radar target.
Once we were trying to find a buoy while enshrouded in fog near the Race at the eastern end of Long Island Sound. We had a radar target in what should have been the right spot, but it didn’t look like any ATON radar reflection we’d ever seen. This was before we had a good chart plotter. We had to be very careful because of the proximity of rocks, which we thought we could smell, but we needed to get a better fix. As we slowly closed, a sailboat emerged from the swirls. It was tied to the ATON, the skipper afraid to move in the fog. Although this might have seemed like a good idea, it’s illegal and can cause many problems.

A better idea is to anchor near an aid, but well out of the channel. Obviously you can’t do this unless you know that the water is deep enough and there are no obstructions. But at least you know where you are, and it’s easy to tell other boats where you are. Anchor sufficiently away from the ATON so as not to present a confusing target to other traffic proceeding by radar. Not only might this confuse the other navigator as to the location of the ATON, he also might think that he’s seeing an echo of the ATON target and thus maybe disregard the “echo” that is actually your boat.

We continue to closely monitor VHF 13 and 16, and when appropriate we broadcast securités giving our location in reference to the ATON. One negative of this tactic is that if something does come your way, it’ll be difficult to move quickly if needed. You’ll have to get your anchor up — fast.

Fog probably will find you sooner or later. Plan now, prepare now. You’ll be glad you did when your world leaves you.

Tom Neale is technical editor for Soundings and lives aboard a Gulfstar 53 motorsailer. You can buy his book, “All in the Same Boat,” and his two-disc DVD, “Cruising the East Coast With Tom Neale,” at

This article originally appeared in the June 2012 issue.