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Diamond of a Dive
Some of the world's most exotic, faraway dive
destinations feature hundreds of islands where divers can see jellyfish,
sponges and a wide variety of marine life in clear visibility. But there's
one place where can you see those creatures, along with an abundance of
quartz crystals — and it's in a freshwater lake in In one of the most
geologically complex areas of the world, Arkansas' Lake Ouachita (Wash'i
taw) is in the middle of the Ouachita National Forest with about 1,000 miles
(1,600 km) of shoreline with no residential development other than four
marina/resort projects. This lack of human development helped rank the lake
as one of the top three cleanest lakes in the nation and allowed the
development of freshwater jellyfish and sponges. Besides the
approximately 200 islands in the 40,100-acre (16,040-hectare) man-made lake,
divers can also explore numerous submerged mountaintops and abandoned
settlements in one of the few North American mountain ranges that run east
and west. West of the natural spas of Hot Springs and just north of the only
diamond mine in North America, the Lake Ouachita region has long been a
destination for "rock hounds” collecting rare natural minerals. One
dive site in the lake includes one of the largest veins of quartz crystals
in the world. A More than 450 million years ago, an ocean
covered this area of Over thousands of years, the In the early 1930s, the government began
buying up land at $30 per acre to create the lake. Many towns were relocated
and by 1953 the 1,100-foot- (333-m-) long Blakely Mountain Dam was in
operation. The
In addition to attracting Many of the local dive
centers have invested in pontoon dive boats to take their classes out to a
variety of underwater settings. Some dive boats have training platforms
attached to the underside of the boat. After the boat reaches a clear,
shallow area near an island, the platform is lowered to the desired depth,
away from bottom silt. After the student divers perform their skill
demonstrations, the group then leaves the platform to explore different
sites on each dive. The main shore entry
for divers is at the far end of the Blakely Mountain Dam. A long series of
steps lead from a parking area down to the water and then continue deep into
the lake's depth. From the submerged stairway there are cables laid out in a
path to a series of sunken boats and vehicles at a variety of depths. This
area has some of the clearest visibility in the lake with no current from
the hydroelectric dam. The rock face around the dam can reach about 190 feet
(58 m) deep. Water visibility varies
around the lake, but increases everywhere past the first thermocline, up to
40 feet (12 m). Despite warm surface temperatures during the summer months,
the water temperature can plunge as much as 20 degrees Fahrenheit (11
degrees Celsius) past the thermocline, so divers need proper thermal
protection when diving deep. With boat access, there are several popular
dive sites around the lake. Zebra Rock is named for
its abundance of vertical veins of white quartz that give the appearance of
zebra stripes in the rock face. Divers can look through the loose rockslide
below the veins to find quartz crystals. When the mountains were
being formed, the uplift pressure on a section of hard sandstone caused the
rock to fracture into a checkerboard pattern at what is now called
"Checkerboard Point.” The large cracks between Checkerboard's square
boulders provide protection for many small fish that, in turn, attract
bigger fish for divers to observe. Unusual Sights Below
the Surface From late May through
October, divers can expect to see swarms of small freshwater jellyfish (craspedacusta
sowerbyii) swim by them. These bell-shaped hydrozoa are translucent with a
white or green tint and are usually less than 1 inch (25 mm) in diameter.
They feature four long tentacles for swimming and many shorter ones
in-between for feeding on zooplankton. These thimble-sized jellyfish do possess
nematocysts to harpoon prey, but they aren't big enough to penetrate human
skin. Originally from The best time to see
the jellyfish is in September after several hot summer months. They can be
seen at depth and floating on the surface from the middle of the lake to the
shoreline. Another underwater
rarity at the lake that divers get to see is the freshwater sponge (spongilla
demospongiae). The sponges are most noticeable in the fall season and can
get to "saucer” size in the lake. They are usually light tan to
green, thin and look like a sponge attached to rocks and tree trunks. The multicellular
animal acts as a sieve to filter microscopic life from the water. Like the
jellyfish, the sponge dies in the late fall, but not before forming a
seed-like body called a gemmule that is immune to freezing and drying. This
gemmule can be transported by wind, water and birds' feet to other bodies of
water. A Fishy Mix While A problem the lake faces from another
invasive marine species from Their needle-like body,
resembling a freshwater version of a barracuda, allows them to easily
maneuver through the thick vegetation to quickly ambush prey or to dart for
cover when threatened. To combat the problem
of hydrilla, the Corps of Engineers is turning to another imported creature.
The Pakistani hydrilla leaf-mining fly's larvae (hydrellia pakistanae)
burrow into the leaves of the plant. Each larva can destroy nine to 12
leaves during its feeding cycle. The corps is treating 13 areas with the
tiny fly that resembles a gnat in size and hops along the water surface
rather than flying. The Arkansas Game and Fish Commission is also stocking
the lake with thousands of grass carp, a fish that prefers to eat hydrilla. With the abundance of game fish, Geo-Float Trail Because of its many
unique geological features, the Corps of Engineers has published a brochure
guiding boaters along a 16-mile (26-km) "Geo-Float Trail” that
explains many of the natural formations of the lake. Many of the stops
listed are also some of the lake's most popular dive sites, such as
Checkerboard Point, Zebra Rock and Whirlpool. With an abundance and wide variety of marine
life, both large and small, Getting There To Lake Ouachita State
Park, from Hot Springs in central Arkansas, travel three miles (5 km) west
on U.S. 270 and then 12 miles (19 km) north on Arkansas Highway 227 to the
park. Contact Information: Corps of Engineers
(COE) COE National Recreation
Many
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Story
and photos by David Prichard and Lily Mak
Diving
the 
