by Neil Lucas Most divers who travel to the aptly named white continent head for the Antarctic Peninsula, where the relatively mild climate and natural diversity make adventure possible. But for a lucky few — scientists, researchers and the occasional filmmaker like me — an unexplored world beneath the ice of Ross Island, on the western side of the continent, can be accessed from the American Antarctic research base of McMurdo Station. Here, the water is not open, but covered with permanent sea ice several feet thick. And for 10 weeks in 2008, this station was my home and workplace. Known affectionately as “Mac Town,” McMurdo is a sprawling U.S. research center. It houses a group of National Science Foundation workers, and with a winter population of about 250 people, it’s Antarctica’s largest community. We were on the frozen continent filming and photographing for the series Life, a new mega-project for the BBC and Discovery Channel. It’s a staggeringly beautiful place with the smoking Mount Erebus volcano as a backdrop and the ominously named, but harmless and dormant, Mount Terror as a neighbor. On a still day, the air is so clear it seems like you can almost touch mountains that are actually more than 50 miles away. Getting there was an adventure in itself. As we sat in the Antarctic passenger terminal in the Christchurch, New Zealand, airport, videos warning about ultraviolet radiation from the sun, snow blindness, the need for sunblock — and most important, how to keep warm — played a constant loop. We touched down on a beautiful summer evening at Pegasus Field after an eight-hour flight on a giant Boeing C-17 Globemaster. With our 75-piece film kit in tow, including a custom-built underwater motion-control rig — the first of its kind in the world — we were transferred to the base in Ivan the Terra Bus, an enormous all-wheel-drive, three-axle, off-road vehicle. Dive coordinator Rob Robbins, a 30-year Antarctic veteran, is in charge of diving operations at McMurdo, and he took me for my very first dive at Little Razorback Ridge, a two-hour drive over the ice. The trek here became a daily routine, and with ice about 6 feet thick, a tracked drilling vehicle with a 4-foot- diameter drill bit had to come along to bore our dive holes. The holes themselves were filled with uninviting slush with practically zero visibility. But after clearing the mire, an extraordinary world stretches out in front of you. Diffused light filters down through translucent, vivid blue ice, while to the rear, shafts of brighter sunlight shine down through the hole that’s the only way in and out of the frigid water. A stop line of checkered flags and strobes ensures that you can find your way back, but divers here were not attached to a safety line, as there was little current. A lot of our filming was done just beneath the ice, but when we ventured down to about 115 feet, the water had a surprising clarity I’d never experienced at that depth. We were diving over the shoulder of an extinct volcano, but the shelf was alive with an array of colorful marine creatures. Crabs scuttled between soft corals, sponges and sea anemones, while purple sea stars clambered over black volcanic rocks. Jellyfish hung in the water column and ghostly ice fish, kept alive in a frigid ocean with the help of antifreeze chemicals in their bodies, peered out from behind clusters of wispy anchor ice that rise from the seabed toward the ice shelf above. Some animals such as sea urchins, that were too slow to avoid the anchor ice formation, were actually enveloped in the ragged crystals. They were trapped in see-through coffins that eventually floated up and became snacks for passing seals. A dead seal pup on the sea floor attracted life from everywhere. Red sea stars, giant brittle stars and purple sea urchins had their tiny tube feet working overtime to be first at the dinner table. Squirming white Nemertean worms and swarms of shrimplike amphipods joined the rush, and a few days later, the scene was covered with a writhing mass of ghoulish scavengers. Back on the surface, a bright-yellow portable hut was dragged over the dive holes to provide shelter for the surface crew and a temporary kitchen to brew hot chocolate and soup to revive the divers. If any of the holes were unused for a short time, Weddell seals would pop up, curiously look around, then dart back down again, their eerie songs filling the sea. Even after blustery days, mild frostbite and the occasional retreat from an icy storm, the experience here was well worth the effort. I’ve been diving in some truly amazing places, but although Antarctica is the most difficult, the surprising diversity and exploratory vibe definitely make it the most exhilarating as well.

Go Now: Antarctic Peninsula's Top Dives

We can’t all head for McMurdo Station, but we can explore this fascinating continent in our own way. The Antarctic Peninsula is where the majority of diving takes place. It’s an underwater realm unlike any other, inhabited by unlikely giants and graceful seals. This secret world below the ice is every bit as colorful as the tropical reefs, and these 10 dives will help you discover it. — Lisa Eareckson Trotter

Cuverville Island, Errera Channel The eastern side of this island is a fantastic wall, which drops to more than 400 feet. Due to the many icebergs that transit the Errera Channel, the top 30 feet is scoured, scrapped of any life by the passing ice. But below this, some of the more impressive invertebrates of Antarctica appear under giant kelp. On the island’s northern side, just in front of the landing site, a shallow bay is a great place to encounter penguins. Cape Wellmet The sheer cliffs on the northern side of Vega Island are some of the most spectacular sea walls around the peninsula. Due to its steep drop of more than 300 feet, the wall is protected from the normal ice scour that affects the area. Covered in life, stalked tunicates extend outward, pale-colored notothenioid fish rest on top of sponges, nudibranchs creep upward and soft corals are abundant. Sewing Machine Needles, Deception Island These natural structures, just south of Baily Head, were originally an arch, but now, after volcanic eruptions, stand as a pair. There’s a wall down to 60 feet, where it shelves briefly, then continues to 90 feet. The wall’s top part has little life, but travel deeper and discover sponges, nudibranchs, hydroids and snails. Look out into the open sea for the chance to see chinstrap penguins returning to Baily Head. Neptune’s Bellows, Deception Island This is the narrow entrance into the caldera of the volcanic Deception Island. Part rock and ash slope, part vertical wall, this 100-foot dive offers sea urchins and brittle stars by the thousands lining the slope. The wall is covered in soft corals, sponges and tunicates — and their No. 1 predator, sea spiders. Additionally, leopard seals can occasionally be seen cruising the area.   Governoren Wreck, Enterprise Islands The wreck of a Norwegian whaling transport vessel, which sank in 1916, creates a protected environment for Antarctica’s most delicate creatures. The ship lies on its side in 60 feet of water, with its outer edges scoured each winter by the ice. Sea squirts, sea cucumbers, anemones and sponges cover every inch, while large, discarded whale bones — which also provide a great hideout for small fish — surround the ship. Mikkelson Harbor A steep slope drops away well past recreational-diving depth here, on the western side of an old whaling station. The slope is lined with giant kelp and other algae, and you’ll also find a wide variety of animals. Dorid nudibranchs feeding on the many types of sponges is common, as are prehistoric-looking giant isopods. Big animals such as leopard seals and humpback whales are commonly seen here, as are orcas. Paradise Harbor A steep wall near the Almirante Brown research base is covered in nesting shag birds and extends 190 feet below the water. Terrebellid worms extend their tentacles for food, nudibranchs and sea spiders search the wall for sponges and tunicates, while shrimp pick through the filamentous algae attached to many of the animals. Later in the season (October/November) curious shag chicks leaving the nest often dive down to meet divers. Port Lockroy This place, just west of Weinke Island, is a world unto itself. It’s never touched by large icebergs, yet it is fed by glacial flow. Thousands of giant isopods move across the seafloor, which is littered with whale skeletons. Anemones and sponges use the stable surfaces for attachment, but the bottom is home to soft-shelled clams. Glacial ice floating in the harbor and the presence of penguin colonies make this area a leopard seal haven. Bahia Paraiso, Arthur Harbor This sunken Argentine transport vessel lies on its starboard side in up to 70 feet of water. Like most wrecks, it offers incredible protection from the elements and ice, allowing sponges, tunicates and sessile jellyfish to thrive. Being a relatively recent wreck (the ship sank in 1989) it also has artifacts strewn across the bottom, such as lifeboat davits, parachutes, sinks and toilets. Pleneau and Booth Islands Booth Island creates the western wall of one of the most scenic passages in Antarctica, the Lemaire Channel, while Pleneau Island is just south of this passage. This area boasts fantastic invertebrate life, but is also a great place to see Weddell and crab-eater seals. Both islands have penguin colonies, and during the summer months, leopard seals feast here — not only on the penguins, but also on the krill, which are abundant.

Need to Know

When to Go The summer offers abundant marine life. The winter offers more ice-diving opportunities. Conditions Early spring and late summer (remember, the austral seasons are reversed) offer the best visibility, although not the 300 feet found under the winter ice. Summer visibility is between 10 and 20 feet, and the average water temperature is between 29 and 32°F. Operators Water Proof Expeditions offers diving and photography expeditions (www.waterproofexpeditions.com). It also offers a PADI Polar Diver specialty course. Oceanwide Expeditions (www.oceanwide-expeditions.com) is teaming up with Diving Unlimited International (DUI) to offer a special trip, beginning March 6, 2010. This dive-intensive itinerary is geared specifically toward advanced divers. Space is limited, so call 800-325-8439 or e-mail faith@dui-online.com to snag your spot. Price Tag The 12-day DUI trip ranges from $9,500 to $13,000 per person based on cabin choice. Water Proof Expeditions trips start at $8,195 per person, double occupancy.

Get the Shot

In polar waters, camera batteries will have about half the power they normally would, so remember to buy new batteries, and recharge often. Because of the extreme temperatures, it’s also best to leave your camera and housing outside (sheltered of course) to avoid condensation. Silica gel bags, like the ones you find in shoeboxes, also help soak up moisture, so you can use them in your housing. To find out what camera setups Neil Lucas and Lisa Eareckson Trotter use in Antarctica, read Camera Kits for Cold Water.