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WINTER 2016
LIFE
AQUATIC
W
hile most humans try to
avoid sharks, the surge in
popularity of shark diving in
the past 10 years shows that
divers are enthusiastically
traveling the world
intentionally seeking them out.
North Carolina’s Outer Banks are a prime location
for diving with sharks. Over the centuries, many ships
met their demise there due to war, weather or human
error as well as by becoming artificial reefs. These
wrecks have morphed into prolific reef communities
with abundant marine life from every link in the food
chain, and sharks are the dominant predators.
Drawn in by the bountiful food supply, numerous
species — including blacktip, sandbar, bull and
occasionally hammerhead sharks — can be found on
these wrecks. But the stars of the show are the plentiful
sand tiger sharks (
Carcharias taurus
).
With small, piercing eyes that seem to stare at
you from every direction and rows of ragged teeth
protruding from a cruel smile, the sand tiger’s visage
is reminiscent of a Hollywood villain’s. But looks can
be deceiving; these sharks are actually docile and
sedate animals that do not startle easily. Careful divers
who respect the animals’ space will be able to achieve
proximity without needing bait or chum. Because of
the sharks’ mild disposition and the ease of finding
them, encounters are almost guaranteed.
Geography plays an important role in producing
the great diving opportunities off the North Carolina
coast. The Gulf Stream heads north along the Western
Atlantic, eventually colliding with the barrier beaches
that are the Outer Banks. In the summer water
temperatures can reach 80°F, with the average on the
bottom hovering in the mid-70s°F. Visibility can exceed
100 feet on a good day, and the norm is around 60 feet.
The combination of warm, clear water, historic wrecks
and plentiful sharks and other marine life makes for
world-class diving.
Even after spending hundreds of hours in the water
with sand tigers, I still get a rush from being among
these menacing-looking but gentle sharks. On a given
dive only a handful may be on a wreck, while on
another there may be too many to count. Each year in
mid-July on the wreck of the
Caribsea
, east of Cape
Lookout, sand tigers ascend from the bottom higher
into the water column, where the water is clearer
and warmer. On more than one occasion I have seen
nearly 75 sharks, all females, gently swimming into the
current in a schooling formation. It is unknown why
they do this, but the sight of it is permanently etched
in my mental logbook.
The aggregation of sand tigers on the wrecks is
most likely due to the reliable source of food the
shipwrecks provide. The wrecks may also serve as
navigational aids during the sharks’ migrations. Dean
Fessler, educational director of the Shark Research
Institute
,
explained it this way: “Sand tigers migrate
long distances up and down the East Coast, heading as
far north as Maine in the summer and south to central
Florida in the winter. They detect the electromagnetic
fields the wrecks emit and use them as waypoints along
their route, much like we would use a GPS.”
Whatever inclinations sand tigers have for the wrecks,
recreational divers are happy they have them. Being
surrounded by a plethora of toothy sharks while exploring
a historic shipwreck makes the diving experience all the
more fascinating and educational. As Fessler added, “It’s a
history and biology lesson all in one.”
Also known as ragged-tooth sharks or gray nurse
sharks, sand tigers are found worldwide, predominantly
in temperate and subtropical waters, including the
Atlantic coasts of North and South America as well as
South Africa, Australia and Japan. Juvenile sand tigers
WRECK DIVING WITH SAND TIGERS
Below:
A sand tiger shark stretches its jaw while swimming through
the wreck of the
Aeolus
28 miles off the coast of North Carolina.
Opposite:
The
Aeolus
is a reliable site for diving with
sand tigers; they are often seen swimming inside the
wreck, and diver presence does not disturb them.
Text and photos by Mike Gerken