From our regular columnists

The Great Hammerhead Shark

January 06, 2015 - 14:09
The story is found: 
on page 53

First described in 1837 by the German naturalist  Eduard Rüppell, the great hammerhead shark (Sphyrna mokarran) is the largest of the hammerhead shark family and can reach a length of over 6m (20ft), although some specimens have been seen to be much larger than this. However, with overfishing, the great hammerhead is usually observed to be much smaller than this.

The curious shape of the hammerhead shark has aroused much speculation over the years and it is now widely recognized that the shape of the wide hammerhead shape (called the cephalofoil), has adapted over the millions of years to be aid-specific to their main prey—stingrays, eagle rays and other

Great Lakes: A Haven for Wreck Divers

January 06, 2015 - 13:57
The story is found: 
on page 12

There are other areas of the world with well-preserved shipwrecks, but the Great Lakes has the monopoly on sheer mass, variety and relative ease of access. Very few known dive-able wrecks are much more than a few hours boat ride from a decent restaurant, a chain hotel or a decent-sized town. Isle Royale, in Lake Superior, is a notable exception, but most wreck dive sites in the Great Lakes do not demand an expedition set up to reach.

I had lived in North America for a few years before I gave the Great Lakes much thought.

Florida Manatees: Sirenians of Crystal River

January 06, 2015 - 13:51
The story is found: 
on page 16

A winter’s dawn is a special time to be on Kings Bay, for as the first rays of the Florida sun appear over the horizon, they light up the soft mist on the warm waters of the bay and create an ethereal, almost mystical, feeling. Listen carefully and you will hear the gentle ripples from the swirl pools formed by the paddle-like tails of the sirenians, as they make their way towards the freshwater springs that are the source of Crystal River.

The arrival of the manatees usually coincides with a rising tide and heralds their return from feeding on the sea grass of Kings Bay and Crystal River.

Tonga's Humpback Whales

January 06, 2015 - 13:48
The story is found: 
on page 51

Our skipper, Ali, carefully maneuvered the boat into position and cut the engine, shouting, “Go, go, go!” at the top of his lungs. And go we did—straight into the deep blue water, with cameras held in vice-like death-grips and onto the path of over a dozen mature and rather excited humpback whales.

Humpback whales average around 14m long and about 35 tons in weight―that’s a lot of mass coming at you―but there was no time to feel scared or even count these huge submarine-like mammals, because we were finally witnessing one of their famed heat runs, when a female humpback has signaled

Jonas Brandt—From Cars to CCRs

January 06, 2015 - 00:11
The story is found: 
on page 35

The CEO of Poseidon discusses his move from the automotive industry to diving, big data, the role of automation, safety and the future of rebreather diving.

"I want to give divers the time to think before they act, based on the huge task load under water. But primarily it is the underwater experience that is the key for future innovation."
— Jonas Brandt

Cold Water Photography

December 31, 2014 - 18:48
The story is found: 
on page 85

Perhaps one of the most difficult, but also most rewarding aspects of all underwater photography is to be able to photograph an animal, or fish, in this instance, in its preferred habitat, without inducing any undue stress or obvious invasion of the creature’s life space.

Firstly, it is much better to stay well clear of the subject and its habitat, approach the subject slowly and sympathetically, and at least this way you are able to keep off the seabed or wall without causing any unnecessary damage.

Scuba's Silent Killer

December 31, 2014 - 18:44
The story is found: 
on page 70

It was a beautiful Caribbean day, water conditions were excellent but Anna was feeling confused. Water had started to seep into her mask and, although she knew how to clear it, somehow she was unable to get the water out. She started to ascend.

Concerned, the divemaster followed her up, signaling to Pauline, the other diver in his charge, that she should wait and he would come back. On the surface, Anna removed her regulator, adjusted her mask, gathered her thoughts and decided she had been foolish.

St. Abbs & Eyemouth

December 31, 2014 - 18:36
The story is found: 
on page 61

Marine conservation has always been important around St. Abbs and Eyemouth when a voluntary ban on the removal of shellfish was first imposed by divers back in the early 1970s with many diving clubs supporting this move.

Located just 15km (9 miles) north of the English border, the reserve now extends from the Hurkar Rocks at Eyemouth to St. Abbs Head and includes 7km (4.5 miles) of coastline and out to the 50 metre (165ft) depth contour.

But I can't be bent

October 21, 2014 - 20:03
The story is found: 
on page 82

One might be forgiven for assuming that as a certified diver, one would understand the science and common-sense behind the basic guidelines governing our approach to decompression stress. After all, a good part of a diver’s initial training (and, hopefully, much of the curriculum for more complex programs), explained the vagaries of breathing compressed gas underwater.

The issue with diving—­at least for this discussion­—is that as a diver descends in the water column, he or she has no option but to breathe compressed gas. Because of this, the inert gas contained in whatever is being breathed is stored in the diver’s body.

Reporting culture

October 21, 2014 - 19:33
The story is found: 
on page 53

“…The real reasons people don’t provide a higher level of detail are two fold: privacy and legal culpability” was the response recently when I posted a blog ( about the need to collect more detail when looking at diving incidents so that the community, the agencies and academia c

We need to be able to raise the awareness and knowledge of those involved in the sport so that they can truly take responsibility for their own actions.