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The Bahamas, a stunning nature lover's paradise,

spread over more than 100,000 square miles of the Atlantic Ocean.

About 150 miles from Florida's southeastern coast, it's

3 ,000 islands, islets, and caves Fringed by white sandy

beaches and calm turquoise waters, were forged over millions of years.

The islands of the Bahamas rest on two massive banks of

limestone, nearly two and a half miles deep, and created by

ancient marine sediments, such as sand and the skeletal remains of coral reefs.

Just 30 of the Bahamas' 700 islands are inhabited by

humans. Twenty-seven national parks spread throughout the

archipelago and provide protection for critical habitats

and endangered species, such as the rock iguana.

The Bahamas is roughly the same size as New York State

and is home to a dazzling array of diverse ecosystems.

Thick forests, twisty mangrove swamps, and the deep and

mysterious vertical submarine caves, known as blue holes.

But perhaps its most breathtaking ecosystems lie under the

clean blue water, the world's third largest barrier reef,

measuring 190 miles long, provides food and

shelter to more than 160 species of coral and fish.

Shallow coastal waters nurture ancient creatures, perfectly

adapted to life on the sandy bottom. But the waters of the

open ocean belong to sharks.

For a diver, the Bahamas will give you for sure a guarantee

that you're going to see some sharks. So if you're a diver

and you have never seen a shark Bahamas, guarantee you that.

Some 40 species of shark cruise these clear blue Bahamian

waters.

These are nurse sharks, Caribbean reef sharks, and

where the shallow turquoise waters give way to the deep

blue, one of the open ocean's great wanderers, the oceanic

whitetip shark.

Oceanic whitetips are stocky, heavy set creatures, reaching

weights of 370 pounds and lengths of up to 10 feet,

and are not to be confused with their smaller cousins, whitetip reef sharks.

Oceanic whitetips typically prowl the deep waters far from

shore. This shark stays close to the upper layer of the

ocean.

Its large, rounded dorsal fin breaking the surface.

Its dark, lifeless eye the size of a baseball.

The legendary oceanographer Jacques Cousteau called these

powerful, silent animals the most dangerous of all sharks.

It is a belief held by many and stems from what has been

called the worst shark attack in history. In 1945, a United

States naval ship called the USS Indianapolis was sunk by a

Japanese submarine, leaving about 900 men drifting in groups

in the waters off the Philippines.

Survivors of the torpedo attack recounted how sharks,

believed to be oceanic whitetips, preyed for days on both

the dead and the living.

Oceanic whitetips are pelagic animals. They inhabit those

parts of the sea that are neither close to the bottom nor

near the shore.

The open ocean is like a desert with little life and little

food. To survive out here, oceanic whitetips need to be

bold, opportunistic hunters, urgently investigating any

possible source of food. Some sharks will bump potential

prey before mounting an attack, and there are stories of

marauding oceanic whitetips fearlessly circling and bumping

uneasy divers.

In the open ocean, conserving precious energy is essential

for creatures on a boundless search for food. Oceanic

whitetips swim slowly, though they are capable of powerful

bursts of speed when in pursuit of fast-moving prey, such as

tuna, barracuda, and white marlin. In this vast expanse

of the open sea, there is nowhere to hide, and oceanic

whitetips are equipped with large triangular serrated

teeth used to clench and tear apart their prey.

Like all sharks, the oceanic whitetip has an acute sense of

smell. As it swims, water passes into its nostrils on the

undersurface of its snout and across sensory

cells, allowing the shark to locate prey by scent.

Incredibly, each nostril can detect smells separately. The

shark is able to identify the direction of a scent by which

nostril detected the smell first.

Oceanic whitetips swim with an entourage of pilot fish,

so named because they were once believed to lead or pilot

larger fish to prey.

Pilot fish follow the sharks to feed on skin parasites

and leftover scraps of food. They also conserve energy by

hitching a ride in the slipstream created by the larger fish.

This shark has a tag attached to its dorsal fin, which

allows a researcher to collect information about its

behavior.

Because they live so far out in the open ocean, oceanic

whitetips are among the least studied of all marine

creatures. A large-scale tagging operation conducted by

researchers in the Bahamas made surprising findings. Oceanic

whitetips will roam as far as 1,200 miles, then return to

their home base in the Bahamas within a few months, the

first evidence of return migration in these sharks.

Commercial shark fishing is banned in the Bahamas, but when

sharks venture far from these islands, they enter dangerous

waters. Oceanic whitetips are often caught in long lines set

for other species. The findings from this tagging operation

will be used in conservation strategies to protect this

species. The oceanic whitetip was once one of the most

abundant apex predators on the planet, but it is now

considered critically endangered. Overfishing has resulted

in huge declines in their population. Oceanic whitetips are

killed cruelly and illegally for their fins, the costly and

destructive key ingredient of shark fin soup.

Each year, about 70 million sharks are killed. The Bahamas

is one of the few places on Earth where oceanic whitetips

thrive in relatively large numbers, plying the open ocean,

consumed by the endless search for food. But oceanic

whitetips aren't the only sharks that flourish here.

The Caribbean reef shark is one of the largest predators

in the tropical coastal waters off the Bahamas.

Reaching lengths of 10 feet and weights of up to 150 pounds,

Caribbean reef sharks are not dangerous to humans, unless

provoked. They are the main attraction of shark dives, in

which bait is used to lure sharks to within arm's length of

divers.

It's not a dangerous animal because, in reference to sharks,

people feel intimidated when they see a shark, or they're

most likely to think that something's wrong or something's

going to happen. But I'd encourage anybody to feel safe if

they see a Caribbean reef shark, because they scavengers.

They have no interest in humans, so you never see a

Caribbean reef shark attacking a human. If you're not a dad

of sick fish, you have no worries about seeing a Caribbean

reef shark.

A shark, it's magic. It's majesty. It's elegant. It's

excellent. It's a warm, fuzzy feeling that you get because

they're so beautiful. They just glide through the water.

And they've got your little eye, and they look at you, and

they're not interested in you. They're just living their

life. It's like a good neighbor. So how do you feel? You

just feel free.

The experience of coming eyeball to eyeball with these

majestic predators has proved popular, and shark-related

tourism now brings an estimated $40 million annually to the

Bahamian economy. And while humans may not be part of the

food chain of the Caribbean reef shark, another species is

not so lucky. The southern stingray is a favorite food of

the sharks that prowl these waters. They are the largest

rays in this part of the Atlantic, reaching six feet in

diameter. Though they appear weightless, floating over the

sea grass, southern stingrays can tip the scales at more

than 200 pounds.

Unlike most fish, the ray does not have an air bladder, the

internal organ that provides buoyancy in the water. If the

ray stops swimming, it will sink to the bottom, but it is

perfectly adapted to life on the coastal sand flats of the

Bahamas, feeding on mollusks and worms buried in the sand.

Electro-receptors on the underside of the ray detect

vibrations created by buried prey, which the ray uncovers by

blowing water through its mouth and gills and

flapping its large pectoral fins to disturb the sand.

It is a feeding behavior known as hydraulic mining.

The southern stingray is a peaceful fish, but if threatened,

it will raise its long tail like a scorpion to stab

predators with a venomous barb. Divers and waders must

exercise caution to avoid an unwanted stingray encounter. If

you're shuffling your feet through the sand and the stingray

is aware that you're coming, it'll just swim away. But if

you were to suddenly step on one, it would shoot that barb

as a defense mechanism to defend itself. It's apparently a

burning sensation, a very painful sensation, like a

wash sting, but I'd say probably times a thousand.

Meanwhile, near the shoreline is one of the most unique

creatures in the Bahamas, the cassiopeia, or upside-down

jellyfish.

As the name suggests, these jellies live upside down on the

sea bottom. Their ancestors roamed the oceans 500 million

years ago.

Upside-down jellyfish are farmers, offering algae a home among their tentacles.

Algae use photosynthesis to turn sunlight into energy, which

is then absorbed by the jellyfish. By floating upside down

in the shallow water, the jellyfish provides ample

sunlight to the algae, thereby getting itself a free meal.

One jellyfish alone is an extraordinary sight.

Millions of jellyfish, all together, are spectacular.

A dense bloom of thimble jellyfish shimmers in the twilight sea.

Thimbles are the most common jellies in the Bahamas. They

explode in swarms in the late spring, feeding on crustacean

zooplankton and barnacle larvae, which they sting with

venomous threads. The uncoiling of these threads is one of

nature's most remarkable feats. Each thread is armed with a

venomous barb that can fire faster than a bullet from a gun.

These vast swarms of jellyfish appear to be occurring more

often around the globe, either part of a natural cycle or

possibly the result of climate change. As oceans warm, jelly

embryos develop more quickly, and jellyfish populations

explode.

They may have no brains, no blood, and no heart,

but these thimble jellyfish can be a menace.

Swimmers can pass through a swarm of invisible thimble

jellyfish larvae without even realizing it. That is until

the appearance of a nasty, itchy rash, caused by the stings

of young jellyfish no larger than a speck of ground pepper.

As twilight turns to night, an equally mesmerizing sight unfolds on the reef.

Tom Tate. Thousands of them.

It's something that makes you belong. You are surrounded by

life. Life is all around you, and that's what you feel under

the water, you know, a big school of fish. And if you move

slowly and calm, they let you be in the middle, and you feel

surrounded by life, very powerful life. The sea never stops,

never gets tired, so it's a special feeling, yes, very

strong.

Each night, shortly after sunset, these Tom Tate migrate off

the reef, to the sandy seagrass bed, where they will prey on

small bottom-dwelling invertebrates, such as shrimp, crabs,

and mollusks. Just before sunrise, they will return, en

masse, to the safety of the reef.

Tom Tate are just one of about 150 species of marine fish,

known as grunts. As their name suggests, these fish make a

grunting sound that is caused by the grinding of their

teeth. The peculiar noise made by a grunt is not unlike that

of a pig.

The creatures of the ocean are locked in a daily battle for

survival, and like many fish, Tom Tates swim in schools to

protect themselves from predators. Targeting individual prey

from a tightly packed school is no easy task for a visually

oriented hunter. For the Tom Tate, there is safety in

numbers. Swimming in unison, the fish may appear as a single

large creature to would-be predators, such as groupers and

sharks. Schooling also helps the Tom Tate forage for food on

the sandy sea bottom. Thousands of eyes are better than two,

and can mean the difference between finding prey or going

hungry. There is another reason why fish swim in schools, to

conserve energy. Those at the back of the school are pulled

along by the slipstream created by their neighbors,

conserving precious energy needed for this nightly forage.

Schooling fish maintain these stunning synchronized

formations by using what's called a lateral line, cells

along the head and body that are sensitive to gentle

currents and vibrations. As a fish swims, it displaces

water, which creates ripples. When those ripples hit the

lateral line of another fish, it is able to detect both the

direction and the speed of its neighbor. This allows the

school to turn with astonishing precision, and to close

ranks tightly in the presence of a predator.

A cloud of sand is stirred up by one of the largest

predators in these waters, the nurse shark. These bottom

-dwelling hunters can reach lengths of up to 14 feet. For

divers, getting close to even a smaller nurse shark can be

exhilarating. Of course you can feel the power, the speed

and the strength. They maybe are five feet, but these guys

can swim very fast in a very explosive way. Something for a

diver is completely impossible. They are very peaceful and

one of the beautiful creatures underwater.

The nurse shark is an apex predator in the Bahamas. Only

larger sharks feed on these strong hunters. At night, it

prowls the sandy bottom, using a whisker-shaped organ near

its mouth, called a barbell, to detect shrimp, squid and

lobsters. It sucks them into its mouth with tremendous

force. And swallows them whole. Then expels inhaled sand

through its gills. As the night begins its retreat, the

nurse shark will return to the submerged ledges on the reef,

to rest up for the next nighttime hunt.

Another day breaks in the Bahamas.

These islands sit atop a thick bed of limestone, comprised

of sand and the broken skeletal remains of marine organisms.

Limestone is porous, and salt water from the surrounding

seas penetrates the rock beneath the island's surface.

During past ice ages, fresh rainwater, made acidic by carbon

dioxide in the air and soil, percolated down into the earth.

It mixed with the salt water, eating away at the

limestone, to form sinkholes hundreds of feet deep.

As the earth warmed and oceans rose, sinkholes filled with

salt water, creating dark and mysterious underwater caves

that may now unlock the secrets to the earth's past, and its future. Blue holes.

The Bahamas contain the highest concentration of blue holes

on the planet. In the dark waters, deep below the surface,

is an ecosystem unlike any other on earth.

A thin layer of fresh rainwater sits atop a denser layer of salty marine water.

The freshwater lens prevents oxygen in the air from reaching

the salt water. Yet somehow, extreme life forms manage to

thrive in these deep oxygen-deprived waters.

Cave diving scientists have discovered colonies of microbes

that are toxic to most other organisms. By studying these

hardy bacteria that are able to survive in the anoxic waters

of blue holes, researchers can deepen their understanding of

what life was like on the planet more than three billion

years ago, when earth was an oxygen-free environment and

bacteria the primary life form. Similar inhospitable

conditions exist on distant planets and moons. The

mysterious blue holes of the Bahamas may hold the key to how

life is able to survive in oxygen-free environments on earth

and beyond. These blue holes also act as a time capsule.

Deep sheltered waters that are low in oxygen are ideal for

protecting fossils. The skeletons of ancient crocodiles,

tortoises and bats have all been found here remarkably

preserved. Without blue holes, much of the fossil record

of the Bahamas would be gone, destroyed by hurricanes and

exposure to the elements. For divers, each descent into a

blue hole is an opportunity to visit a strange and distant

past. This kind of feel like you are diving through the

arteries of Mother Earth. You are going through a history of

geology of our planet. It's like flying and getting into

another time. You stop thinking about anything else.

These vast underwater chambers house monumental formations

that hang like glowing icicles. These are stalactites. They

are formed when dissolved limestone in the water escapes

into the air and hardens as calcite. Over time, miniscule

amounts of calcite build up and drip from the cave ceiling.

Mineral-rich water that seeps through the cave ceiling or

drips off the end of stalactites creates stalagmites, which

rise from the cave floor. Each of these remarkable

sculptures begins with a single drip. You feel, in another

word, you are in a cave. You are no longer in the normal

living realm of your days. You are under the water in a

cave, sometimes 600 feet in into a cave, and you are just

enjoying but also very focused on what you are doing,

exploring a new territory.

Few have explored the farthest reaches of these vast and

twisting underground waterways. Cave diving is extremely

dangerous. In the darkened depths, it is easy to become

disoriented. A single wrong turn or equipment failure, and

you're doomed. Hundreds of divers have perished in caves

like these. It's believed that less than 20% of the 1,000

blue holes in the Bahamas have been explored. These

dark underwater passageways remain one of Earth's final

frontiers.

On the island of Eleuthera, another unusual underwater

environment continues to fascinate scientists.

An inland saltwater lake, separate from the ocean, is home

to an extraordinary and intelligent creature. This is the

Caribbean reef octopus. The octopus is believed to be the

smartest of all invertebrates on the planet. Experts believe

they have the intelligence, memory capacity, and skills

development of a three-year-old child. In captivity, they

have managed to unscrew a bottle cap to remove a crab inside.

In the wild, an octopus can remember the location of a

predator and stay clear. When faced with a predator, the

octopus is armed with multiple defense strategies. It is one

of the few creatures on Earth able to completely alter its

appearance in a flash. Thousands of color-changing cells

just below the surface of the skin allow it to blend in with

its surroundings. A complex network of muscles and nerves

controls projections on the skin, creating bumps and spikes

that match the texture of plants or rocks. Predators, such

as sharks and dolphins, may swim over the octopus without

even noticing it. If discovered, an octopus can make a fast

getaway by sucking water into its mantle and expelling it

through a siphon tube to jet through the water. When

cornered, an octopus will release a cloud of black, foul

-tasting ink to blind and disorient an attacker and even

dull its sense of smell, while the octopus makes its escape.

And if caught by a predator, the octopus has a remarkable

last line of defense. It is able to lose an arm, then

miraculously regrow it later, without lasting damage.

In this saltwater lake, there are few predators, and the

octopus swims freely on the lookout for crabs and mollusks.

It grips prey with powerful arms as long as eight feet, then

paralyzes it with nerve poison secreted in its saliva. The

oldest known octopus fossils date back almost 300 million

years, well before the age of the dinosaur. Creatures like

these have roamed the oceans, adapting perfectly to their

surroundings. The octopus has three hearts. Two pump blood

to the gills. The third keeps circulation flowing for the

organs. When the octopus swims, the third heart stops

beating. It crawls along the seabed to conserve precious

energy.

In the shallow seas that flank the islands of the Bahamas,

sunlight penetrates the surface, nourishing the seagrass,

which in turn nourishes one of the ocean's gentle giants,

the manatee. These peaceful, slow-moving creatures are

sometimes called sea cows, though they actually evolved from

the same land animal as the elephant more than 50 million

years ago.

At 10 feet long and reaching weights of up to 1,200 pounds,

the average adult manatee is similar in size to a large

polar bear.

A powerful tail pushes the manatee along the sea meadow.

It will cover three to five miles in an hour. Manatees are

voracious herbivores and will spend up to 12 hours a day

feeding on seagrass, weeds and algae. A manatee can consume

10% of its body weight in plants every day. Coarse hairs

around its lips enable it to detect and grasp plants,

especially helpful when the manatee is feeding in murky

water. Scientists believe the bristles are as sensitive as a

human fingertip.

Like all marine mammals, manatees must surface to breathe air.

A resting manatee can stay submerged for as long as 20

minutes by slowing its heart rate by 80% to conserve oxygen.

When the manatee does take a breath, it replaces 90% of the

air in its lungs. In comparison, humans replace just 10%.

Manatees are sluggish and docile. They have no defense

mechanisms because they have no natural predators. And yet

these placid creatures are at risk of extinction.

They are illegally slaughtered by hunters, seeking their

hides, carelessly entangled in fishing nets and accidentally

killed by motorboats in the shallow coastal waters favored by these gentle beasts.

At the surface, another air-breathing marine creature

catches a breath. The loggerhead turtle is the largest of

all hard-shelled turtles in the sea, and is named for its sizable log-shaped head.

This female is a bird of prey. She is about five feet long.

Her shell is as broad as a table for four. Loggerheads swim

slowly, but are capable of bursts of up to 20 miles an hour

when fleeing predators such as sharks. You feel like small

compared to them, and they are so fast. They are so agile

under the water. We, as divers, even with the best buoyancy

that we can achieve, we are not so good swimmers as them.

This loggerhead turtle has company. The remora, or

suckerfish, are highly specialized creatures. A modified

dorsal fin on the top of its head acts as a suction cup and

allows it to cling on the turtle for a free ride. Remoras

will feed on parasites and bacteria on the turtle's shell, as well as leftover scraps.

The loggerhead's days are spent soaring to the surface

for air, then down to the bottom to search for prey.

Powerful jaws crush jellyfish, conch, and crabs. Older

loggerheads, such as this female, show no fear of divers.

Loggerhead turtles have an enormous range. An adult female

will migrate thousands of miles from its feeding ground to

lay its eggs on the same beach where it hatched years before.

These warm and shallow waters are home to another long

-distance traveler. The green sea turtle. Like its cousin,

the loggerhead, its homing behavior is remarkable. Tiny

magnetic particles in the brain allow it to use the Earth's

magnetic field to navigate the open ocean,

to locate the exact stretch of coastline where its life began.

Hatchlings have been observed tasting the sand as they

scurry down the beach to the surf. It's believed this is to

create a chemical memory of their birthplace so they may

return to the same spot in 12 to 15 years to continue this

cycle of life.

Life in the open water of the Bahamas is a struggle. By

returning to a successful nesting site to lay its own eggs,

the sea turtle increases the odds of survival for the next generation.

Unlike most sea turtles, the adult green sea turtle is a

true herbivore. It feeds entirely on algae and seagrass,

which colors its fat green and gives the green sea turtle

its name. They eat as much as five pounds of seagrass a day

and control the growth of these flowering plants. They are

the cattle of the sea. Without the green sea turtle, this

sandy sea floor would be invisible.

Beautiful white sand beaches fringe the islands of the

Bahamas, comprised mainly of the shells and skeletons of

marine organisms. The fine sandy bottom extends for miles

into the sea and underpins the oceanic food chain. Plants

that grow in the sand provide food and protection for

fish, which attract one of the ocean's most playful and

intelligent creatures, the Atlantic spotted dolphin.

It's not that easy to get close to the dolphins unless they want it.

Of course they feel like they don't know you, they don't

know if you're a threat, but when they feel curious and they

feel safe, they can swim around you very fast, very agile,

they are like surfers under the water. I wouldn't say

spiritual, but it's a loving feeling inside when you embrace

something like that, that has such intelligence and such

power and speed. It's a good feeling, sometimes you get a

little nervous because it's a smart animal and you never

know what it's going to do. Atlantic spotted dolphins are

social animals. Traveling through the shallow coastal waters

in pods of 10 to 100, groups can include males and females,

adults and young dolphins that are yet to develop their

trademark spots.

Like whales, dolphins breathe air, taking in oxygen at the

ocean's surface through a blowhole on top of the head. And

just like whales, dolphins are conscious breathers. They

never fall completely asleep. One hemisphere of the brain

always remains awake, so even while sleeping, the dolphin

is able to surface for air and remain alert to predators.

Their brain-to-body ratio, which is believed to be a measure

of intellect, is second only to humans. Dolphins use touch

and posture to communicate.

These three touch fins to stay in contact as they accelerate

through the water. Swimming belly up can signal a male's

interest in mating.

In a large social group, efficient communication is

essential. Dolphins use clicks and whistles to keep in

touch. Each member of the pod uses a signature whistle to

identify itself, a useful tool for a mother keeping track of

a young calf. Adults emit loud pulses of sound to discipline

young dolphins or even scare off sharks. Even more

impressive is the way these dolphins see with sonar. They

are expert at echolocation, making clicking sounds, as many

as 500 per second, that travel through the open ocean,

bouncing off of potential prey and echoing back to the

dolphin to reveal the size, shape and location of a

potential meal. This sensory system is so precise that

dolphins have been employed by the U.S. Navy to locate

underwater explosives. The complex social network of

dolphins is designed for one purpose, survival. Dolphins

will coordinate hunts, herding and then harvesting schools

of fish. A whistle then signals the catch to other dolphins

in the group. Spotted Atlantic dolphins have also been seen

taking part in post-mortem rituals that researchers believe

are consistent with grieving. Adult dolphins will use their

backs and heads to buoy up recently deceased calves at

the surface, as if unwilling to part with the dead. Adult

dolphins will hold on to their dead young for as long as 30

minutes before surrendering them to the sea, where they will

nourish other creatures. Energizing the food chain and

ensuring new generations will thrive in this beautiful and

complex underwater world.

From rich coral reefs and deadly underwater caves to apex

predators of the open ocean and majestic creatures linked to

a prehistoric past, the Bahamas is a treasure trove for

explorers and one of the many wonders of the great blue

wild.

In the Bahamas we have great visibility, end of story. I

think what is special about it is the geological landscape

and the fact that it is unspoiled and it's really unspoiled.

It's a magical place, very still. You feel a good strong

contact and a balance. About 70% of the planet is water, so

diving puts you really close to what it's feeling and living

this planet.

The Bahamas are a great place to live. The

Bahamas are a great place to live. The Bahamas are

a great

place to live. Thank you for watching!