Adaptive scuba diving is a growing sport. This growth is propelled by the dedication of highly motivated advocate/divers like Cody Unser.

A year after she became paralyzed due to Transverse Myelitis - a rare inflammation of the spinal cord thought to be caused by infections or immune system disorders - Cody took up scuba diving as a way to keep up with her active family. She was thirteen years old at the time. Now, sixteen years later, she and her mother Shelley Unser head the Cody Unser First Step Foundation and its subsidiary dive programs Cody’s Great Scuba Adventures and Operation Deep Down.

Imagine that you have a sponge. Really, go ahead! In fact, imagine that you have one of those fancy scrubby sponges that is green on one side and yellow on the other. This sounds silly, but sponges absorb water similarly to how scuba divers absorb nitrogen. The sponge analogy will help you to understand the fundamentals of nitrogen absorption while diving.

Normally when people think of the word slug, they think of something slimy and undesirable, but that’s not the case when it comes to the underwater world. Nudibranchs, kind of like a sea slug, come in virtually every color and combination of colors and are extremely beautiful. Although most of the time they are quite small, they are so awesome that this makes up for what they lack in size. Here are 10 pretty cool things you might not know about nudibranchs.

Scientists have created highly detailed maps charting the seasonal movements and population densities of 35 species of whales, dolphins and porpoises -- many of them threatened or endangered -- in the crowded waters of the U.S. East Coast and Gulf of Mexico.

the crystal coast, N.C. – Feb. 22, 2016 –The Crystal Coast of North Carolina – home to America’s Coolest Small Town, the No. 4 Best Spring Break Destination in the U.S. and some of the state’s Top 10 Beaches – is once again in the running for a major destination accolade. USA Today 10Best has nominated Cape Lookout National Seashore as one of the Nation’s Top 20 National Park Beaches, with the potential for this Coastal gem to be named the No. 1 favorite, Friday, March 18.

            Reminiscent of times past where wild horses roam freely on deserted beaches, Cape Lookout National Seashore, with its famed lighthouse, offers escapists a 56-mile stretch of underdeveloped shimmering beaches accessible only by boat.

            “Those who love and live in the Crystal Coast cherish Cape Lookout as one of the Southern Outer Bank’s most treasured gems,” said Carol Lohr, The Crystal Coast Tourism Authority executive director. “The beaches are unspoiled and stunning, and nothing beats the view of the Spanish Mustang horses running on Shackleford Banks.”

            “What an honor it is for Cape Lookout to be recognized in 2016 when the park is celebrating its 50^th anniversary and the National Park Service is celebrating its 100^th anniversary,” said Patrick Kenney, superintendent of Cape Lookout National Seashore. “We hope those who have experienced this special place will take the time to vote.”

Fans of Cape Lookout National Seashore may vote once a day at http://www.10best/awards/travel/best-national-park-beach/. Voting concludes Monday, March 14, at 11:59 am EDT.

If you think that just because you're swimming in freshwater that you're safe from sharks, you might want to think again.

Not only do ferocious bull sharks roam as freely through freshwater as they do in saltwater, but bull sharks have been found as far inland as Indiana in the Ohio River and Illinois in the Mississippi River. Along with the great white shark and the tiger shark, bull sharks are among the top three species most likely to attack humans. Yikes!

There are also at least five other species of true river sharks, which are exclusive to freshwater rivers in Southeast Asia and Australia. All river sharks are capable of growing to over 10 feet in length, and are more than capable of consuming a human.

Feeding sharks for the benefit of divers is becoming more and more common, but is controversial. New research suggests that feeding in areas with several different sharks, over time, leads to one species increasing in numbers at the expense of the others. Published in PLOS ONE⁽¹⁾, the study looked at the Shark Reef Marine Reserve feeding site in Fiji from 2003 to 2012.

Eight species of shark regularly visited the site in 2003: bull shark (Carcharhinus leucas), grey reef shark (Carcharhinus amblyrhynchos), whitetip reef shark (Triaenodon obesus), blacktip reef shark (Carcharhinus melanopterus), tawny nurse shark (Nebrius ferrugineus), silvertip shark (Carcharhinus albimarginatus), sicklefin lemon shark (Negaprion acutidens), and tiger shark (Galeocerdo cuvier). By 2012, there were more individual sharks visiting, but fewer species. The winner was the bull shark. The smaller tawny nurse shark, silvertip shark and sicklefin lemon shark became very rare visitors.

At 9 foot long, not including the tail, tiger shark (Galeocerdo cuvier) Harry Lindo is not exactly on the small side.  It’s not Harry’s size that is exciting scientists and shark enthusiasts, nor a photograph taken in 2009 by Ian Card showing a shark – suspected to be Harry, trying to eat a 150 lb juvenile tiger shark off the coast of Bermuda.  Between 2009 and 2012 researchers tagged 24 tiger sharks with satellite transmitters in the Challenger Bank, which lies just off Bermuda in the Atlantic Ocean.  In study lead by James Lea (The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center) and team of international collaborators, those shark movements have been compiled and analysed.  Harry, it turns out, is one heck of an ocean wanderer.  In just over 3 years Harry swam over 44,000 kilometres – that’s more than the circumference of the Earth (just over 40,000 kilometres).  Harry’s track is the longest recorded for a tiger shark, and probably the longest ever published for any shark species.

With tentacles up to three metres long and covered with stinging cells, it’s better not to get too close to the Lion’s Mane jellyfish. It’s body can be 2 metres across, making it one of the largest species of jellyfish.

The tentacles are arranged in eight bunches, with each bunch containing over 100 tentacles. The oldest tentacles are often coloured dark red. They have a very severe sting that can produce blisters, irritation and muscular cramp and may even affect respiratory and heart function. Fragments of tentacles, left on buoy ropes for example, retain their stinging power.

The tragedy unfolded unusually slowly for an aviation catastrophe: The crew fought to control the USS Macon for more than an hour. US naval officers threw fuel canisters overboard in an attempt to reduce the weight of their vessel. The canisters imploded on their way to the ocean floor. Meanwhile, the Macon -- the largest rigid airship ever constructed in the United States -- sank inexorably downward, the safety of the Moffett Field hangar just within reach.

The Macon hit the water surface only five kilometers (three miles) off the Californian coast, along the latitude of the Point Sur lighthouse near Monterey, on Feb. 12, 1935. The zeppelin broke apart and sank into the deep water. Two of the 83 crew members died -- the low number of deaths is likely due to the fact that the Macon sank in slow motion.

Diatoms are unicellular algae that are native in many waters. They are a major component of marine phytoplankton and the food base for a large variety of marine organisms. In addition, they produce about one fifth of the oxygen in the atmosphere and are therefore a key factor for our global climate. However, these algae, which measure only a few micrometers, have yet another amazing ability: they can "smell" stones.

Jellyfish blooms are increasingly causing problems. In Korea, the number of accidents and financial losses caused by jellyfish is estimated at 300 billion won (£1.8 m) per year. To combat the jellyfish, Korean researchers led by Professor Hyeon Myeong are using a team of robots, called JEROS (Jellyfish Elimination Robotic Swarm). These slash and grind the jellyfish, killing 900 kg an hour.

Jellyfish cause the fishing industry to lose money by breaking fishing nets. They sting swimmers. They block the seawater cooling systems of power plants. In 2009, a ten-ton Japanese trawler capsized after the three man crew tried to haul up a net loaded with jellyfish.

The Mauve Stinger, or Luminescent Jellyfish, is a beautiful jellyfish. Often coloured purple, you can find it around the world in warm and temperate waters from around 12 to 30 m.

This jellyfish is the most venomous in the Mediterranean. However, its sting is usually limited to the skin surface with local pain which lasts for one to two weeks. In some cases the sting can leave scars, or pigmentation of the skin lasting for several years. Should you be stung by a jellyfish, rinse the area with vinegar for 30 minutes. If vinegar is not available use sea water: don’t use fresh water. Remove any tentacles left on the skin.

Read about dive sites and diving operators in over 90 countries, from Argentina to West Papua. All with ratings and reviews from divers: find the best places to go and companies to dive with. We're here to help you plan your next dive trip: use the SCUBA Travel diving guide.

Hermit crabs scuttle about the sea-floor using someone else’s shell for a home. They always use empty shells and never kill the original occupant.

When the crab becomes to large for its shell, it looks for another. When it finds a likely looking one it will try it on. If the shell doesn’t fit, or is too heavy, the crab returns to its old shell and continues it search.

It's that time of the year again, folks. The time where we all vow to improve ourselves — one way or another — and get a fresh start with the onset of a new year! You've heard the repeat offenders (and probably made them yourself, be honest): lose weight, quit smoking, eat healthier, save money, drink less... the list goes on. So here at Scuba Diving magazine, we decided to come up with a list of our own! You know you're a diver when...

A Diver's List of New Year's Resolutions

Human beings do not have gills, but swimming underwater as if we did has long been a basic urge. With his “amphibious respirator unit,” a prototype for what the world now calls SCUBA gear, Christian Lambertsen, Rutgers Class of 1939, made diving feasible for millions of people.

He also helped win a war.

With Cuba on the cusp, the island that time forgot; we ventured in, concerned that the Cuba now, will be changed forever with the advent of Americans ready to pour in.

Very keen to go after seeing 60 minutes program 2 yrs ago with Anderson Cooper, reveling in the ‘untouched reefs and marine life with loads of Caribbean Reef sharks’ swimming all over him, I had to go!!

After many long months of sorting out the Treasury Department documentation on the legal way to travel to Cuba. We could participate in the Ocean Conservation ‘people to people’ program legally with our marine biologist on board for diving Gardens of the Queen!

Lucky for us, Fidel Castro was an avid diver, 20 yrs ago he declared Jardines de la Reina a marine sanctuary and is highly protected today!

Nothing was easy about getting to Cuba or getting to Gardens of the Queen, it was all part of the wonderful adventure ahead of us!

With Cuba on the cusp, the island that time forgot; we ventured in, concerned that the Cuba now, will be changed forever with the advent of Americans ready to pour in.

Very keen to go after seeing 60 minutes program 2 yrs ago with Anderson Cooper, reveling in the ‘untouched reefs and marine life with loads of Caribbean Reef sharks’ swimming all over him, I had to go!!

After many long months of sorting out the Treasury Department documentation on the legal way to travel to Cuba. We could participate in the Ocean Conservation ‘people to people’ program legally with our marine biologist on board for diving Gardens of the Queen!

Lucky for us, Fidel Castro was an avid diver, 20 yrs ago he declared Jardines de la Reina a marine sanctuary and is highly protected today!

Nothing was easy about getting to Cuba or getting to Gardens of the Queen, it was all part of the wonderful adventure ahead of us!