Diving Medicine By Dr. David Sawatzky A seizure is a sudden surge in electrical activity of the brain that alters how an individual feels or acts for a short period of time.  In a classic ‘grand mal’ seizure a person looses consciousness, all of their muscles contract for up …

Diving Medicine By Dr. David Sawatzky In the last column we looked at epilepsy and seizures.  However, epilepsy and seizures are a relatively rare cause of loss of consciousness.  The most common cause of loss of consciousness is fainting (syncope) and it results in one of every 30 visits …

Diving Medicine By Dr. David Sawatzky In this column we will look at the breath-hold diver who suddenly looses consciousness in relatively shallow water.  These individuals often die from drowning.  This phenomenon has been called ‘shallow water blackout’ but the term should be avoided – it’s confusing.  Initially shallow …

Diving Medicine By Dr. David Sawatzky Frequently, I receive reader questions. The following (edited) enquiries raise several issues of interest. Does Nitrox Have a Taste? Should Nitrox taste any different from regular air? I’ve noticed a difference. Air is odourless and tasteless in contrast to Nitrox, which I found …

Diving Medicine By Dr. David Sawatzky In the last two columns I reviewed inert gas narcosis.  High Pressure Neurological (Nervous) Syndrome (HPNS) is a similar problem that is experienced on deeper dives.  It is a difficulty that recreational divers will never experience but advanced technical divers are increasingly performing …

Diving Medicine By Dr. David Sawatzky Every diver knows that when they go diving they need to pee.  They also know that any cold water diver who claims never to have peed in their wetsuit is either lying or has logged very few dives. Finally, it’s fair say that …

Diving Medicine By Dr. David Sawatzky In the last column I talked about the reasons urine production is increased while we are diving and what we can do about it.  In this column I will continue that discussion by looking at other reasons divers are almost always dehydrated during/after …

Diving Medicine By Dr. David Sawatzky In any discussion on dehydration, the topic of electrolytes must come up.  So what are electrolytes?  In Stedman’s medical dictionary an electrolyte is defined as “any compound that, in solution, conducts electricity and is decomposed by it; an ionizable substance in solution”.  Ions …

Diving Medicine By Dr. David Sawatzky All of us enjoy diving or we would not be doing it. Often we feel better when we are diving. A subset of divers seem to really enjoy diving deep on air. Is diving addictive? Narcosis is a fascinating topic and supports the …

Diving Medicine By Dr. David Sawatzky Every year approximately 100 people die in North America while diving, and another 100 die while diving in the rest of the world.  Diving is a relatively high ‘risk’ activity.  By that I mean there are many ways in which you can be …

Diving Medicine By Dr. David Sawatzky In the last column I looked at diving fatalities and noted that poor buoyancy control was a significant factor.  Buoyancy control is by far the most difficult skill to master in diving and the easiest one to lose.  Therefore, in this column I …

Diving Medicine By Dr. David Sawatzky I was recently consulted on the case of a commercial diver who presented with cold, white, painful fingers after walking outside on a cold windy day.  When the diver was questioned it was discovered that they often experienced similar symptoms while diving and …

He’s not a shark expert, hasn’t studied their behaviour, and doesn’t champion their cause, although he was once bumped by a shark not looking where it was going. Good job our man Sawyer doesn’t bear a grudge. Text by H.E. Sawyer  – Illustration by Peter Dahl-Collins I’m sorry, but …

Dave Williams was just a kid when he made a farsighted commitment that eventually saw him blast off for the international space station. And his boyhood dive training and years of experience in the sport backstop his record setting spacewalks. Text by Dave Williams   My helmet lights reflect …

Jarrod Jablonski talks with Michael Menduno   Credit Where Credit Is Due In my interview with explorer Jarrod Jablonski in DIVER Vol. 37 Number 1, I incorrectly stated that Jablonski and his team from Global Underwater Explorers were the first to video the USS Atlanta in 430 feet (130m) …

Wearing a blackout mask Diveheart founder Jim Elliott had an epiphany of the senses. In that tactile moment he understood that diving is not for eyes only. Text by Andrew Leibs – Photographs Courtesy Diveheart   On the surface, scuba diving seems purely visual. The very phrase conjures images …

Reserves are going down, which may mean prices go up? And how might that affect the future of mixed gas technical diving? The answer is up in the air. Text by Jeremy Heywood and Lee Newman   The future of mixed gas technical diving may be uncertain due to …