The new Ventura is an extremely versatile BCD. This lightweight back inflation BC which weighs less than 5 lbs is fantastic for travel. But it is also a great BCD for local diving as well. Whether diving in Cozumel or Catalina the Ventura is designed from the ground up to be the best BC in class.

At only 4.7 pounds, it’s much more than the typical lightweight BC. The Ventura aircell is made of Double Coated TPU, which basically means it doesn't absorb any water and it doesn't gain water weight after repeated dives, a real plus when traveling. This Double Coated TPU material is extremely durable, and as a result we are able to increase the warranty on the bladder from Two years to Five years.

The Ventura is rugged, extremely compact, exceptionally stable, and features our uniquely designed integrated weight release system.

The QDS Weight System is a very simple yet effective weight system that allows 16 pounds of ditchable weight.
More features. Less weight. Perfect for travel.

My first dive was in a murky lagoon in Key Largo, Florida. I bumbled along with a herd of excited new divers, stirring up the soft, oozing muck at the bottom of the lagoon. Diving was fantastic, but I didn't see much. For most of the dive, I was enveloped the brown cloud of bottom sediment that the divers had stirred up. Our finning technique, the flutter kick, was quickly reducing the visibility in the lagoon.

The flutter kick is an inefficient kick. It propels water above and below the diver, which does not contribute to forward motion and wastes energy. The downwards propulsion of water also disturbs sand and other bottom sediment, leading to a reduction in visibility. The frog kick is a much more effective kick, and is easy to learn with proper instruction. Click through this tutorial to learn the basics of the frog kick.

Our sea creatures are in trouble. What with warming temperatures, pollution, plastic debris and over-fishing, the oceans need protecting more than ever before. And governments are becoming more committed to creating marine reserves. But are they just paying lip service to the problem or really addressing it? Too often a marine reserve allows commercial fishing and other exploitation. A marine reserve which isn’t really a marine reserve at all.

The new IUCN Red List reveals that growing human pressures on whale sharks and slender hammerhead sharks are putting these species at an increasing risk of extinction. Both the shark species are now listed as Endangered.

Numbers of whale sharks (Rhincodon typus), the world’s largest fish, have more than halved over the last 75 years as these slow-moving sharks continue to be fished and killed by ship propellers.

Although conservation action in India, the Philippines and Taiwan has ended large-scale fishing of whale sharks in these countries, they continue to be fished in other locations, including southern China and Oman. As whale sharks and tuna are often found together, the sharks are frequently caught by tuna fishing boats.

Unregulated fishing is also behind the fast-falling numbers of the distinctive slender hammerhead shark (Eusphyra blochii), whose shape makes it easily get tangled up in fishing nets. This species has moved from Near Threatened to Endangered on the IUCN Red List.

Although it is difficult to say how many individuals remain, recent surveys of fish markets in Indonesia found only one slender hammerhead shark among approximately 20,000 sharks of other species. A similar pattern is expected throughout Asian countries where coastal fishing is intense and largely unregulated.

“It is alarming to see such emblematic species slide towards extinction,” says Jane Smart, Director of IUCN’s Global Species Programme. “These new IUCN Red List assessments emphasise how urgent it is for the conservation community to act strategically to protect our planet’s incredible diversity of life.”

A full update to the IUCN Red List of Threatened Species, including assessments of many other species, will be announced at the IUCN World Conservation Congress 2016 to be held in Hawaii from 1 to 10 September.

Whale sharks are found in all tropical and warm seas except the Mediterranean. The rise of dive tourism in many areas is making the fish more valuable alive than dead in some locations, including at Ningaloo Reef in Western Australia, Donsol in the Philippines, Placencia in Belize and Isla Contoy in Mexico. In all these places, and in other countries like the Maldives, India, Thailand and Malaysia, the whale shark is protected. However, the whale shark migrates long distances out of the safe areas and into the fishing zones.

It's a fact: we need oxygen to live. It's because of the way our cells use oxygen that we are able to breathe, exercise, and even think. In each of our cells, structures called mitochondria take the oxygen which diffuses in from our blood, disassemble it into its two component atoms (remember, oxygen - O2 - is composed of two oxygen atoms), and then hook some available hydrogen nuclei to them to form water.

The process releases energy, which is used for all functions of life. The problem is that in disassembling the oxygen molecule, it involves a step in which an extra electron is hooked on. This forms an intermediate called a superoxide anion, and this is a bad actor. It is highly reactive, and it will make mincemeat out of most other molecules it comes in contact with.

These anions are like coals in a furnace: as long as they are contained, we get lots of safe chemical energy; if they get out we get a great deal of damage. The mitochondria are designed to contain these superoxide anions, but just in case some get loose, there are a host of protective chemical reactions designed to sop them up and prevent them from doing any damage.

Besides producing excessive amounts of the superoxide anion, elevated tissue oxygen levels also affect a variety of other biochemical reactions which may affect oxygen toxicity in ways that are only beginning to be understood. Tissue-protective mechanisms and biochemical reactions are tuned to life in an atmosphere containing 21 percent oxygen, or 0.21 atmospheres absolute (ata) oxygen partial pressure. (See sidebar: "Remember Partial Pressure?", page 34.) As the partial pressure increases above this comfortable 0.21 ata, protective mechanisms are slowly overwhelmed and biochemical reactions are affected. This may eventually result in "oxtox," or oxygen toxicity.