Where the
cold waters of the Labrador current meet the clear warm
Gulf Stream waters, lies a place called the "Graveyard of the
Atlantic". For as long as men have sailed the seas, they have
found
their way to the beautiful Barrier Islands of North Carolina.
But
their arrival has not always been a pleasant one. For many of
these
vessels, the hazardous shifting shoals, German U-boats, and just plain
old sailor error have determined their fate. Weather in the
Graveyard
is unpredictable and can change in the span of a few minutes.
The
shifting sand shoals continuously move about, providing a challenge for
even the seasoned mariner. The tragic irony is that many of
these
ships who dared to take their chance close to the shores of North
Carolina now sit on the bottom of the Atlantic, a testament to Man VS
Nature. North Carolina is considered the #1 wreck diving site
in the
United States by many, and our large variety of underwater flora and
fauna bathed in warm blue Gulf Stream waters rivals popular Caribbean
diving resorts. Visibility on many of these wrecks is usually
in the
70 foot range, but days of 100+ feet of visibility is not uncommon.
From
the Northern tip of the Albemarle Sound to the Southern tip of Cape
Fear, the North Carolina coastline boasts over 2,000
shipwrecks. Some
of these are so close you can dive them by just walking out into the
water from the shore, while most require you to own a boat or take a
charter out. Our wrecks vary from 14th century pirate ships,
to World
War I and World War II casualties, to modern ships sank as artificial
reefs.
During
the summer months, our typical weather pattern is similar to the
tropics ~ hot and sunny in the morning with scattered showers in the
evening. Sometimes, we'll enjoy a ridge of high pressure that
drops the humidity and eliminates the chance of rain. Though
rare, we may also get a few days in a row of overcast skies and
rain. When we get hurricanes, they typically occur in late
September, with the threat diminishing in mid October. These
are
few and far between, and should have little impact on your diving
plans. What affects our diving most here in North Carolina is
...the wind.
North Carolina's coast, similar to the entire east
coast...or any coast for that matter...has issues with wind.
The
magic of an island is that, at any given point, there is always a
windward side and a leeward side. That means depending on
which
way the wind is blowing, it's usually calm enough to be diving
somewhere. Unfortunately, that's not the case with a
coastline. In the summer, the prevailing winds in North
Carolina
come from the southwest, offshore, so there is no protection offered by
land. So when the wind blows hard, the seas get rough in
North
Carolina.
There is,
however, a difference in "wind
chop" and "swell".
Wind chop is a sea condition categorized by lots of waves, very close
together that have, as the boat captains say, "no back on them",
meaning they are like miniature ski jumps, where the boat rides
smoothly up one side and then comes crashing straight down the other,
as opposed to a swell, where the boat gently rides up one side of the
wave and gently down the other side. Wind chop can start and
stop
rather suddenly here off the North Carolina coast and is, as the name
implies, completely dependent on how hard the wind is
blowing.
"Swell" on the other hand, refers to big, wide rollers that have a lot
of space in between them. Swell is often caused by offshore
storms and doesn't fluctuate as quickly as chop. So a
four-foot
swell is not an issue, but a four foot chop can be downright
uncomfortable. Add the two together? Forget about
it.
Your
perception will vary according to where you're used to diving, but here
are some "North Carolina" guidelines: 1-2 foot seas produce
calm,
lake-like conditions. 2-3 foot seas make for a pretty good
day on
the water, though it is a tad bumpy. Solid 3 foot seas is
doable
not miserable, whereas 4 foot seas are probably doable but
miserable. 5 foot seas are not fun at all and if you are in 5
foot seas you might be on your way back to the dock instead of on your
way to the dive site. Anything 6 foot or over, if you left
the
dock at all (which is unlikely), there is little chance of getting in
the water.
On average, during the summer, 10% of all North
Carolina days are "blown out" (not diveable). The most common
condition in North Carolina is 2-3 foot seas, which compromise about
50% of our dive days here in North Carolina. The remaining
40% is
evenly split between marginally miserable, miserable, and positively
perfect. A good rule of thumb is - the actual size of a swell
is
2/3 of what you think it is. What you think are 3's are
probably
2's. 6's are 4's, 8's are 5's, etc. This caveat is
to save
you the embarassment of claiming you were diving in 8 foot seas in
North Carolina to those of us who know better. Right now
somewhere in the Caribbean, there is absolutely some guy saying out
loud to those around them, "Pffft.
I was too out diving in 8 foot seas in North Carolina!"
What
winds produce what seas, you ask? Out of the Southwest, winds
exceeding 15 knots (about 17 mph) will create sea conditions in North
Carolina that over a few hours, build to the point of being
undiveable. If you're reading NOAA's Marine Forecast, and you
see
words like "light and
variable" or "winds
5 to 10 knots", you're in for a wonderful "dead slick
calm" day on the water. Another common forecast in North
Carolina is "Southwest
winds 10 to 15 knots",
which is a lot like saying "50% chance of rain" in that you're being
provided with information, but in reality, the forecaster doesn't have
a clue about what to expect. Anything over 20 knots, go to
the
cafe, buy yourself breakfast, and sip your coffee all
morning.
While you're sure to be dissappointed that your dive got "blown out", I
can guarantee you that you'll be happier on land than on a dive boat
that day.
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