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Sea Savvy Navigating at Night

Make sure those things that go bump in the night aren’t your boat

Make sure those things that go bump in the night aren’t your boat

The night was blacker than the inside of a cow. The moon sliver had disappeared long ago, and clouds covered the stars. It’s a big ocean, but it can get surprisingly small very suddenly, especially when you can’t see.


The radar sweeps told their tales, but sometimes radar shows what isn’t there and doesn’t show what is there. A second or so of not knowing in the dark can seem an eternity. I like to look out and scan the night regularly. But radar impairs night vision a bit, and sometimes you don’t know whether to keep looking at a mysterious blip for another second or two or to just look across the waves.

On this night the waves were the only thing in that vast world that the radar saw, as sea clutter. I liked that, but I still had my diesel throttled back to low speed. I’ve seen too many containers and barrels and tree trunks floating just submerged, invisible to even good radar. I figure I’ve got more of a chance if I don’t hit these boat-killers quite so hard.

The swoosh came from nowhere. Loud, threatening, not like what you hear from a manatee or a porpoise while you’re anchored in the night. And not like what you hear from a nearby whale, and not the smell of its fishy breath. It was a gigantic sound. I instinctively looked in its direction but saw nothing. Questions flashed: Should I look at the radar, or get all light away from my eyes and continue to peer into the blackness? I glanced at the radar and couldn’t believe what I saw. Where there had been nothing before there now was a target like a battleship, and it was right beside me.

It was a battleship of sorts — it was a submarine. Apparently it had just surfaced. It continued on, running fast and dark. I guess they knew I was there, at least when they got on top. I’d spoken with a ranking submarine officer once, and he told me that, even with their very fine equipment, they often don’t hear a small boat (small to them) on the surface. This is one reason I always keep my engine turned on when running in the dark, even when a nice breeze is drawing the sails. I want to see and hear, and I want others to be able to do the same for me. I always keep my depth finder turned on, too, even when the water is thousands of feet deep. Sending and receiving signals is part of what it’s all about out here in the dark.

Over the years on Chez Nous we’ve developed various tactics for running in the dark. Most pertain to coastal and tributary cruising, not necessarily to transoceanic voyages. They may not be the best for you; this depends on a combination of all the circumstances. And they’re characterized by a certain part of my psyche that always surfaces when it’s really dark: I don’t like things that go bump in the night. It was bad enough when they were under my bed when I was a kid, but out here I can’t hide under the covers. And the bumps are much, much bigger.

I’m OK with being uptight at sea on a dark night. You’ve got to be realistic. It doesn’t diminish my enjoyment of being out there (well, maybe a little, sometimes), and there are times when you have to be out at night to get where you want to go. Safety equipment for nighttime navigation is beyond the scope of this article. However, I’ll pass a few of our experiences on to you hoping that they may help, although you may have developed better tactics and some or all of the following may not be applicable to the circumstances in which you find yourself.


Modern electronics make things much safer at night, as well as at other times. But it’s important to know how to use these devices. Chart plotters and computers with cartography programs, for example, will tell you where you are. An overlay on a radar display can be even more helpful. But most cartography programs and related hardware now have so many features that you actually have to practice to get more than a cursory benefit from them. And there’s nothing wrong with this. It’s fun. But we’re constantly amazed at skippers who are proud to show off their vast arrays of technology around the wheel but come up with a blank look when you ask them to perform a specific task that’s much beyond turning it on. And you can’t learn this at night when danger is closing in on you.

Radars, as simple as they seem and as good as they’ve become, also require practice. This should begin in the daylight under relaxed, safe, non-threatening conditions. Look at a buoy, boat or other potential target and see how it displays. Fiddle with the adjustment controls. Some are automatic, but even they may need tweaking to best deal with varying states of sea clutter, mist, rain and other interference. If you wait until night or other low-visibility conditions, you may not know what you’re not seeing, and adjustments you make may do more harm than good. And these are the times when you need to concentrate on what’s out there, not on fiddling with knobs and buttons.

A great feature of radar is that it can show storms with rain, which make a very distinctive target. People have died at night when unexpected squalls hit. If there’s no light, you can’t see the clouds approaching and may not know what’s about to happen unless there’s lightning. We can easily learn to recognize storms on radar while sitting in a marina.

The movement of other boats and storms — relative to your position, course and speed, as displayed on radar — can be exceptionally confusing. Mistakes in interpretation may be fatal. Learn the principles of analyzing this, and practice in the daylight when you can see if you’re making a mistake. The subject of radar use can fill books, and it’s important to study it. Two books that come to mind are “Radar for Mariners” by David Burch (International Marine/McGraw-Hill), and “Boat Navigation for the Rest of Us” by Soundings contributing writer Capt. Bill Brogdon (International Marine/McGraw Hill).

Night equipment

A good set of binoculars is one of our most important tools. Well-made binoculars not only let you see in the distance, they gather ambient light so that you can see things out there in near darkness that you’d never see with the naked eye or poorly made binoculars. Often just a little starlight or even a lot of phosphorous on breaking waves will be enough. A bearing compass in the binoculars with an internal on/off light is critical.

Other equipment, such as AIS (Automatic Identification System) transponders and receivers, can help other boats detect you and you them, thus avoiding collisions. The various night vision products also help. Among the more impressive (and, yes, more expensive) I’ve seen lately is the thermal imaging infrared equipment by FLIR Systems Inc. ( ). A heat-sensitive camera “sees” in the dark, and the images appear on a monitor at the helm station. A large yacht version with which you can pan and tilt the camera remotely has an MSRP of $8,995. Soon to come will be a version in a fixed housing with an MSRP of $4,995. This technology, however, is adversely affected by rain, as is true with radar.

At the far lower-cost end of this special equipment is Weems and Plath’s new LightDivider ( It’s a divider with a red LED on each arm that illuminates the area on the chart under the arm without unnecessary night vision impairment. (The company says it will be available in early 2007.) And if you’re thinking that you don’t need charts with all your glowing electronics, think again. Indeed, there are electronic displays specially designed to be used at night, but even the best of these can impair night vision to some extent, and we should never be out there without also having paper charts and courses plotted on them.

Some feel that the cost of all of the fancy gadgets is far beyond what they can afford. However, you need to anticipate the results of cost analyses while floating alone in the cold water one night with pieces of a boat bobbing around you.


A spotlight is a critical piece of equipment for nighttime navigation. It not only helps you see and identify objects and aids, it can make you more visible to others. It’s unlawful and extremely unwise to use a spotlight in any manner that impairs the vision of personnel operating another boat. But you can use the beam to carefully look out ahead to see what’s out there, or cast it on your sail, mast, superstructure or hull to be sure that others see you. Beware that when you do this it will probably impair your night vision, especially if not done carefully.

Usually a remotely operated, permanently mounted spotlight is most effective because it can be very strong and powered by the ship’s DC or AC current. Unfortunately, it can be difficult to mount these satisfactorily on some boats. On a sailboat, for example, a light mounted on the main or mizzen mast will reflect off the mast or stay in front of it, impairing the vision of the watch. Also, sails can damage the light or reflect its beam.

Many powerboats have spotlights mounted just under the windbreak of the flybridge. The beam projects almost from under the nose of the helmsman and radiates light over the forward part of the deck. Again, this can be detrimental to vision. On some boats the light is mounted on the bow pulpit, which has advantages. But this puts it relatively low to waves and in a position where it’s constantly being immersed in spray and sometimes green water. Consider all factors when you’re mounting a permanent light.

Hand-held spotlights are the only way to go for many, because of the above problems. I’ve used them on my last four cruising boats, which have been sailboats or motorsailers. Hand-held spots do have benefits. You can hold them out and shine them around stays or other reflective structures so there’s no backlight. The person holding the light communicates with the helmsperson as to where to direct the beam. But I’ve always envied the boats with permanently mounted lights because they’re usually so much brighter.

Unfortunately there is, in my opinion, a lot of marketing hocus-pocus as to the “strength” of both hand-held and permanently mounted spotlights. It isn’t uncommon to see claims of 3 million candlepower or more on the boxes of some very inexpensive lights. I’ve tried a lot of them and have seldom found them to be of much good, for our use. You need a light that throws a beam, often in misty conditions, and illuminates a surface far away, not just a light that makes an indiscriminate mess of glow around you. And the issue of spotlight effectiveness isn’t a suitable arena for toys or numbers games. It can be a matter of life or death.

Reputable spotlight manufacturers take the matter much more seriously. They measure the effectiveness of their lights’ beams with testing equipment that can quantitatively determine such things as the amount of illumination on a surface at a specified distance from the source. This is important.

During the black hours of Hurricane Ernesto I compared two hand-held spotlights. (I know the pretty weather people on television called it a tropical storm, but they weren’t on my boat.) One was an inexpensive “3 million candlepower” spotlight that came with two lead acid batteries, a charging pack, a pouch for the unused battery that was too small for the battery, and an external 12-volt power source. The light’s body flexes if you grip it too hard, and a rubber protective shock strip for the battery came out destroyed the first time I removed the battery. The price was less than $40. What a deal, I thought as I flipped out my credit card for yet another boat-related hit. The other was the new Profiler II by Golight (, which is rated at 440 M (maximum) lux and retails for around $440.

When I compared beams, what they illuminated at what distances, and how well they pierced the swirling mist and rain, I couldn’t believe the difference. The cheap light didn’t hold a candle — so to speak — to the Profiler II. About a week prior, I had compared the Profiler with permanently mounted spotlights by major manufacturers on two boats at a marina. The Profiler outperformed those dramatically, as well. (I had no information about the state of maintenance or power source of the other units, although one was relatively new.)

When the Profiler II beam hits its target, it doesn’t leave a black hole in the middle like many spotlights. Golight accomplishes this with an “H-7 axial filament Blue Vision bulb” and what it describes as a “precision pressure cast aircraft aluminum parabolic reflector.” The company refers to this combination as “Golight NxT BlueFusion” technology. (Reflectors are a critical feature of most lights, but they often are cheaply done and perform poorly.) The spotlight is powered by a rechargeable lithium-ion battery that Golight says gives it up to an hour’s run time in spotlight mode with a two-hour recharge time. A secondary 1-watt LED beam with stated running time of more than 50 hours lets you use the Profiler II like a small flashlight.

You can power this light with the boat’s 12-volt power with an included cable. The light and its accessories, including a battery charger mount are, in a word, rugged. Now I don’t envy the big powerboats with mounted lights so much. I’ve got one that works as well or better than many, and I can take it with me. The cost hurts, but not as much as a collision or grounding. It comes with a strap, and at $440 you’d better believe I wear it whenever I take that light out on deck.

Lights to see what’s aboard

I have almost 30 hand-held lights aboard Chez Nous, because I’ve learned over the past 50 years aboard boats that when I need a light I need it now. It’s also because different lights do different jobs. OK, I’m also a flashlight freak. I’ve loved the things ever since I discovered I could take them under the sheets with me when I thought I heard that bump under the bed.

Small flashlights help you find and do things down below without turning on cabin lights or when there are no cabin lights. Problems at night occur down there as well as out in the water around you. And they occur unexpectedly. It’s also sometimes necessary to light up a small area on deck to find some item that’s “wandered” away. If you can direct a beam rather than turn on deck lights, even if they’re filtered, you might be less likely to impair the vision of the helmsperson. A flashlight that flickers or simply doesn’t come on only contributes to the problem, so I try to buy only well-designed and -built lights. I have specific criteria for this, but that’s a subject for another article.

My current favorite general-purpose small hand-held is Pelican’s SabreLight 2010 Recoil LED submersible ( ). This light is amazing for many reasons, like the fact that you have to worry very little about the bulb or batteries dying. Being an LED, the bulb has a very long life expectancy — 10,000 hours, according to Pelican — and consumes very little power.

A problem with LED lights in the past, however, has been that they don’t throw much of a beam. Some manufacturers have added more and more LEDs to solve the problem, but, in my view, this hasn’t necessarily been that helpful. Pelican’s Recoil technology directs the LED backward to a carefully designed reflector that sends it back out, somewhat like the reflective lenses of a lighthouse. The result is a strong, collimated beam with no hole in the center and without the battery-depleting power consumption of traditional bulbs and configurations.

The light’s battery compartment is exceptionally well-designed to hold the batteries firmly in place against the contact points and to protect them from shock. And there’s yet another neat feature of this light: It’s part of Pelican’s new Photoluminescent series, which means its lens cover glows slightly in the dark so that you can find it. It also can be used as a dive light for depths to 500 feet. The MSRP for the Photoluminescent light is $64.95.

The LightWedge from Weems and Plath is another handy tool. It measures 9-1/4 by 6-3/4 inches, with an optical-grade, clear-acrylic, wedge-shaped lens that reflects red LED light onto a page. There are two brightness settings. With it you can read resource material and charts without interfering with the night vision of those around you and with minimal impact on yours. Its MSRP is $40. We also use the Ultra-Optix lighted chart magnifier (model SV-3LP) for reading paper charts. A magnifying glass with filtered bulb and batteries in the handle, it has a 3-inch lens with 3X magnification and a 6X bifocal insert. West Marine lists it for $11.99.

I don’t mean to de-emphasize the obvious importance of well-placed, permanently mounted green/blue or red filtered night lights powered by the boat’s current. Many boats have these, and they can be very helpful. But the area illuminated by these could be limited, and I have a habit of losing things where the lights don’t shine. Also, if you lose ship’s power you’ll lose the light unless it has an emergency backup power source, as some of the more expensive ones do. Further, even a good filter will still result in some impairment to night vision when a large area, such as the helm station, is illuminated.

We like the gooseneck chart/helm station lights marketed by Weems and Plath. These can be dimmed, are 12- or 24-volt, and can be directed to a specific location to better see what you want with less interference to night vision. MSRP is $180. There also is an arsenal of hand-helds available with night filters. For example, many of the Pelican lights have night filters and can be focused on very small areas.

Lights in the night around you

Light configurations on other boats give information as to the type of vessel, its direction of travel relative to you, and other characteristics, such as whether it’s got a tow. (Many terrible accidents have resulted from the failure of skippers to realize that there’s a tow behind a lead vessel.) Like other aspects of boating, it’s important to spend time learning about the specific light configurations displayed by different types of boats, how these change under varying circumstances, such as a tow or condition of disability, and how their appearance will change as the position of the boat relative to you changes. All of this can be very confusing at night unless you’ve thoroughly learned the configurations. And confusion is a major cause of accidents.

There are various books and charts that show different vessel light configurations and their meanings. Keep one at the helm station, but don’t think you’ll be able to look at it and analyze what’s happening in the dark during an event. This information should be in your head. Weems and Plath’s LIGHTrule can be very helpful for learning lights and as a reference. It’s essentially a slide that shows different light configurations and what they mean. MSRP is $25, and a second generation of this tool is due out.

Even if you know your light configurations, you can’t always rely upon the lights of other vessels to tell the whole story. One early, misty morning we were heading out St. Mary’s Inlet in northern Florida. A huge freighter was heading into the inlet from the sea, and I couldn’t see either a red or green light. I called the freighter on VHF 13 to verify courses and told him I couldn’t see his red and green running lights. He said he’d send someone to check and shortly thereafter replied that they were both working. As we came abreast we realized that we hadn’t seen them because they were so high, and on-deck containers or other structures on the freighter obscured them. To another freighter they probably would have been visible.

We always need consider that one or more lights on a boat might be out or improperly displayed. We’ve found this to be true with all types of vessels; the same is true of lights on aids to navigation. All it takes is an osprey nest to obscure a light. Whenever something isn’t “adding up,” consider the possibility that the signals are wrong and try to verify what you’re seeing and get other information.

Lighted aids to navigation are less complicated than vessel lights, but they also are very important. The color and flash sequence of lighted aids might tell you exactly how to safely proceed. Many a boat has gone aground because the skipper didn’t count the flashes or seconds between flashes. If you’re in an area with lighted aids, study the chart well in advance of approaching them so that you’ll know whether to expect, for example, a flash every 4 seconds or 2.5 seconds or a quick flash, a Morse code series, or whatever else is beckoning.

When the lights of moving boats blink as they dip in the waves and as they move among lighted aids against a shoreside background of reds and greens and automobile lights, the situation can be very difficult to decipher. For this reason, we try to avoid coming into a busy harbor at night unless we’re very familiar with it and really need to do so.

Nighttime confusion

When you’re steaming along in the darkness and all is well, it’s hard to imagine how quickly you can “lose it” to confusion and disorientation. An instinctive uneasiness about being out on the water at night, plus the fact that all of a sudden you realize you’re not sure what’s going on, can turn confusion and disorientation into panic. Preparation helps prevent this. I’ve mentioned some of the areas that require learning. I also should mention a thorough knowledge of the Rules of the Road. We’re required to have a copy on board, but we should be able to react according to those rules without looking them up.

Experience also helps. The more you do it, the more you learn about what to expect. But there’s an aspect of self confidence and preparation that often goes unrealized until it’s too late. In order to figure out what’s happening on the water beyond your boat, you need to be familiar with what’s going on in your wheelhouse or cockpit. You need to be able to locate such tools as binoculars, spotlights and flashlights. You need to know where the chart is lying and perhaps where to find a pencil or dividers.

Before darkness, prepare your steering station so that each item has its own secure, logical place. And use common sense in assigning places for objects. For example, we find that it helps to have the binoculars within immediate reach but not where they’ll fall or be sat upon. We keep the magnifying glass and LightWedge on top of the chart. The spotlight is within immediate reach of whoever is going out on deck to use it. A hand-held flashlight is secured by the companionway so that it’s there for whoever is rushing below. Be sure that all watchkeepers know what’s where. This helps to avoid time lost fumbling around in the dark and impairing night vision by turning on a light to find something.

Standing watch

If possible it’s much better to have at least two people at the helm station when traveling at night. When my wife, Mel, and I had our daughters, Melanie and Carolyn, aboard, night travel was much easier because they could stand watch with us. They had great vision, were alert, and knew what was going on. Now they’ve graduated from college and have jobs, and Mom and Dad have to struggle through the nights alone.

It’s important to not become overtired while traveling at night or any other time on a boat. For this reason we establish watches that work well for us. In establishing a schedule that works well for those on your boat, consider variations in the people and the type and duration of the voyage.

If you have only two people aboard, it’s often best if the person off watch sleeps on a pilot berth at the helm station. If your boat doesn’t have this feature you should be able to quickly awaken your sleeping partner below. This is because if anything unusual begins to occur or if you have any question or difficulty knowing exactly what’s happening, you should get the other person to help.

It’s often best for the other person to step outside on deck — wearing the appropriate safety equipment and with a communications headset if needed — with a good pair of binoculars to both look and listen, away from ambient lights and sounds of the helm station. Sometimes bringing the engine to slow idle helps you hear telltale noises. Some recommend full shutdown, but you have to be sure you’re not going to need to take immediate evasive action and that if you do, that beast in the bilge will start immediately. In other situations it might be better for the second person to be watching the radar and other electronics or the chart while the helmsperson concentrates on the surrounding darkness.

And never hesitate to call another vessel on the VHF, giving your position, course, speed and relative bearing. Try both channels 16 and 13. If you get no answer on either, this can indicate that they’re not keeping adequate watch and are more likely to be a problem.

Being at sea at night often is necessary. It can also be beautiful, therapeutic and refreshing to the soul. But diving under the sheets with a flashlight to avoid bumps in the night doesn’t cut it out here. Learning, good equipment and good practices do. If you and I pass in the night, give me a hail on the VHF. I’ll probably be very happy to hear a friendly voice.

Tom Neale is technical editor for Soundings and lives aboard a Gulf-star 53 motorsailer. You can buy his book, “All in the Same Boat,” at