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The Restless Air
Season of Mists
By Tamia Nelson
tamia@paddling.net
September 21, 2004
Fog has always fascinated me. Early in my life,
when I dreamed of becoming a professional photographer, fog offered infinite
possibilities for dramatic pictures. On crisp autumn days, as I looked down from
the sunny summit of one of the hills near my home, fog defined the contours of my
world in a delicate white tracery, filling each secluded hollow and outlining
every ridge. Once back in the valley, though, I saw fog from the bottom up.
Colors shifted. Hard edges softened. My horizon advanced and retreated with every
change in the wind. Each leaf, twig, and petal sagged under the weight of
countless water droplets. And stray shafts of sunlight transformed spiders' webs
into diamond circlets. Fog was magic.
When I became a commuter, however, the same magic took a menacing turn. Now
fog was my enemy, a malevolent trickster bent on making me late for work —
or worse. I started paying more attention to weather
forecasts then, and I learned a lot about fog. But I lost something, too. My
world was grayer, my life less magical.
Happily, color and magic returned on my rare days off, when I'd flee to nearby
lakes, hills, and rivers. There I rediscovered fog's lighter side. Photography
was still important to me, to be sure, but it now took second place. In the
interval between youth and maturity I'd begun to
paint. Watery landscapes and watercolors are a natural pairing, and I made
the most of every opportunity that came my way. Fog was once more my ally.
Trickster or trusted friend, or both — fog has many faces. It can be as
ephemeral as a threadbare gauze curtain, swaying gently in the first tentative
breezes of a summer's dawn, while offering only token opposition to the rays of
the strengthening sun. Or it can be a gray shroud, clammy, clinging, and opaque,
advancing relentlessly across the open ocean, engulfing all that lies in its
path. In such a fog, even the largest ships become invisible, yet sound is so
magnified and distorted that the bark of a
solitary seal seems like a trumpet announcing the end of time.
In classical mythology, an old man named Proteus, son of the ocean god
Poseidon, slumbered peacefully through his days in a sea-cave, surrounded by
seals. When awakened by intruders, though, Proteus sought to escape capture by
taking the shape of a snake or a wild pig, or even a tree or flame or freshet.
Fog, too, is protean — now it's a curtain, now a shroud, now something
in-between. It's even slipperier than the old man of the sea. Yet if we cannot
hope to capture fog's essence, we can still strive to understand some of its many
manifestations. So let's begin…
In the Beginning
How does fog form? Water is the key — fog is made up of tiny droplets of
liquid water. It's really a cloud brought down to earth. There are only two ways
to grow a fog. You can cool moist air until the water starts to sweat out. (The
temperature at which this occurs is known as the "dew point." If you've ever
watched beads of water form on the outside of a cold glass on a hot day, you'll
know why.) Or you can flood dry air with moisture until it's soaked up more water
than it can hold. Call this the hot-shower approach. In this case, you're not
lowering the air temperature. You're raising the air's dew point, instead. But
the effect is the same.
With this in mind, let's explore the genesis of fog under a variety of
circumstances.
- Invasion from the Sea. Suppose an onshore breeze carries moist
ocean air far inland by day. Then night falls and the temperature drops. What
happens? The moist ocean air cools down, and if it cools below the dew point, fog
forms. This onshore push is one example of "advection fog," and it's a
common summertime phenomenon along the Pacific coast of North America, from
Alaska to northern California. The fog develops in the small hours just before
dawn, often drifting back out to sea on the land breeze. Luckily, it usually
burns off by late morning or early afternoon, but if the onshore push is strong
enough, the resulting fog can hang around for a day or more, accompanied by a
sustained drizzle.
- The Gray Wall. No one who's seen a wall of fog advancing toward her
will soon forget it. In places where prevailing winds bring warm, moist air over
cold ocean water, thick banks of sea fog can form. It's another type of
advection fog. You can expect it in summer in the cold coastal waters of New
England and the Maritimes, and anytime from late spring to mid-autumn in the
Pacific Northwest. A warning: sea fog drifts with the wind, and once you've been
swallowed up by the wall, your visual horizon will be measured in feet or yards,
not miles.
- A Soft Rain's Gonna Fall. Warm fronts drive moist air over masses
of colder, drier air. The resulting rain quickly saturates the cold air, and the
subsequent warm frontal fog will linger until the front pushes the last of
the colder air out. This fog doesn't burn off. How do you spot it coming? In the
northern hemisphere watch for light southerly winds, along with thickening low
clouds and sustained rain. Then look for a good place to camp.
- The Season of Mists. Think of steam fog as the mirror image
of sea fog. Cold, dry air rolls down from the hills and spreads out over warmer
water. Soon tendrils of fog are writhing up from the water's surface. Where sea
fog is frequently menacing, however, steam fog is usually romantic, as ephemeral
as a threadbare gauze curtain. Commonly seen along rugged seacoasts in late
autumn and early winter, steam fog is also a familiar sight on mountain ponds and
lakes in the weeks before freeze-up. And it's at home in arctic waters, too,
where it goes by the colorful name "sea smoke."
Of course, air can move up as well as down, and when warm, moist air is driven
up the side of a mountain, it cools as it rises. At some point, clouds
will form. If you live on the slope of the mountain, you're likely to call these
clouds "fog." A meteorologist will call it expansion fog, since air
expands as it rises, cooling in the process. It's found on the eastern approaches
to the Rockies in late winter and early spring, and in many other places as well.
People who live in the high country soon learn that the foggy-mountain boys were
well named.
- The Season of Mists, Take #2. So far, we've talked about fogs which
form when masses of air move from one place to another. But fog can form in still
air, too. Consider what happens when a rainy day is followed by a clear, calm
night. You go to sleep beneath a tapestry of stars, but you awaken to a gray
dawn. The sun is nowhere to be seen. What happened? Easy. Yesterday's rain
saturated the soil. Then the still, cloudless night permitted heat to radiate
skyward, cooling the damp air near the ground. The result? Ground fog,
also known as "radiation fog." Ground fog can form over water, too. In fact, it's
often seen in river valleys, basins, and inlets, where cold air flowing down from
the surrounding heights cools the surface further. If you think this sounds like
steam fog, you're right. The two processes frequently coincide. Like steam fog,
ground fog is most common in autumn and early winter, and it's usually
short-lived. Unlike steam fog, though, it can only form in still air or
very light winds.
You don't need a weatherman to forecast ground fog. If you can see your breath
on a clear night, expect to find yourself socked in by morning. The
good news? You'll be in the clear by noon or a little later, unless the moist air
is…
- Trapped! This happens most often during temperature inversions,
when a cap of warm air forms over a cooler air mass, trapping it near the
surface, along with any fog. Such inversion fogs are frequent, if
unwelcome, visitors to southern California, where they add to the joys of life in
the fast lane and contribute to the witch's brew of toxins we call smog.
OK. We've seen how fog can form. And we're agreed that — apart from short
paddles through the morning mists on remote and sheltered inland waters —
the best way to cope with fog is to avoid it. But sometimes even the best
intentions come to nothing. After all, the only certain way to avoid fog on the
water is to avoid the water, and that's not very practical advice for a paddler,
is it? So you'd better plan what to do…
When You're Caught in the Fog
Two problems come to the fore immediately. You need to know where you are at
all times, and you want others to know you're there, as well. Easy to say, but
not so easy to do. Fog hides both landmarks and seamarks. And it conceals
vessels, too, from coracles to container ships. It also distorts sounds. Your
first job, then, is to do everything you can to…
- Be Seen. Take the advice of smart hunters and cyclists: wear
high-visibility colors. "International orange" is good, and panels of reflective
fabric make it even better. If your boat and paddle are in-your-face orange,
rather than no-see-um green, so much the better. Carry a waterproof
flashlight "ready at hand" to exhibit "in sufficient time to prevent
collision," as the Regulations for the Prevention of Collisions at Sea
(better known as the "Rules of the
Nautical Road") require. WARNING! Strobes are prohibited by the Rules
in international waters and limited to emergency use elsewhere. But the fact
remains that they're often used by paddlers (and others) who think that being
seen is more important than complying with the letter of the law. It's your call.
Just remember that not all attention is equally welcome. Don't do the crime if
you can't do the time.
If you paddle in waters frequented by motorized vessels and commercial
traffic, a radar reflector can also be a good investment. Don't expect it to work
as well in a kayak as it will when perched high in the rigging of a sailboat,
though. Here, as elsewhere, the Gross Tonnage
Rule applies. Whether you paddle a kayak or a canoe, you're just about the
smallest thing on the water. No matter what you wear and how bright your lights,
you can never count on being seen, nor should you assume that other vessels can
avoid you, even if they know you're in their path. (A container ship traveling at
18 knots can take three nautical miles to stop dead in the water after Full
Astern is rung down.) So it's up to you to keep out of every other vessel's way
— or suffer the consequences.
- Be Heard. When paddling through busy waters in fog, silence is not
golden. Make noise. The Rules require sailing vessels in fog to sound "three
blasts in succession, … one prolonged followed by two short," and to do so
"at intervals of not more than 2 minutes." That's probably good advice for
paddlers, as well. The whistle on your
PFD is better than nothing, though a hunting horn might be better yet. Only
small vessels will hear your "Tally Ho!" of course, and only in the best of
circumstances, but it's still worth the trouble. After all, even a collision with
an 18-foot sailing dinghy that's barely making steerageway will certainly spoil
your whole day.
- Listen Up. Anytime you're not making noise, you should be
listening. Sound travels far over water, and it never carries as well as it does
in fog. Bell buoys, horns, the rumble of marine engines, even barking dogs and
quarreling couples miles away can all be heard with startling clarity. But fog
also deceives. "Lanes of silence" come and go. Direction is almost impossible to
determine. Vessels that are dangerously close sound far away, while a bell
warning of a distant rock seems alarmingly near at hand.
What can you do about this? Stay alert. Weigh the information from each sense
against the evidence of the others. And learn from past experience. Nowhere is
local knowledge more important than it is in fog. The characteristic hiss of the
tide flooding over a shoal speaks volumes to the knowledgeable paddler, even if
it remains a foreign tongue to the novice. All the more important, then, to be
sure that you…
- Stay Found. GPS makes this easy, or at least it makes it easier
than it used to be — so long as the batteries last and you don't drop your
magic box in the water. If that should happen, though, you'll be glad you have a compass and,
just as important, that you know how to use
it. This knowledge, when coupled with an educated guess of your paddling
speed under prevailing conditions and the strength and direction of any current,
will allow you to keep a reasonably
accurate plot of your estimated position. (A lead line or its electronic
counterpart can be an invaluable asset in fog, but few paddlers nowadays carry a
lead, and fewer still have mastered the art of heaving the lead in the confined
space of a kayak cockpit. Perhaps more should.) Needless to say, a foggy day is a
poor time to embark on a long, difficult open-water
crossing.
Are you a novice navigator? Then it's probably better to heed Falstaff's
advice and recognize discretion as the better part of valor. After all, you can't
come to too much harm if you…
Stay in Port. And there's no denying the attractions of a hot drink
downed in front of a warm fire when the world outside the door is chill and gray.
Comfort has its place, even in the life of an adventurous paddler.
Not satisfied to remain ashore during the season of mists? Neither am I. But I
have to admit there's wisdom in the words of the boatmen of the Aran Islands, as
reported by John Millington Synge:
A man who is not afraid of the sea will soon be drownded for he will be
going out on a day he shouldn't. But we do be afraid of the sea, and we do only
be drownded now and again.
A bit unsettling? Of course. But it's a necessary reminder that the sea
sometimes drowns even careful mariners. That doesn't mean that prudent paddlers
will want to bet against the odds, though, does it? So venture out into the
mists, by all means, but do so with your eyes open and your ears tuned to the
hiss of the tide flooding over the shoals.
Copyright © 2004 by Verloren Hoop Productions. All rights
reserved.