The beginning of diving activities stems from humane need and desire to explore. As a result, reports of diving experiences date back to the ancient years. Skyllias (500 BC) and even Alexander the Great (320 BC) are some of the first divers – the latter is reported as the first using diving equipment (a glass barrel).
While free (breath-hold) diving is being used for centuries practically without significant changes, autonomous (SCUBA) diving evolved greatly in the previous century, together with relevant technological advances that allowed that to happen.
Historically, diving has served energy, construction, technology, research, military, food supply, search & rescue and recreation. In Greece, diving has been historically linked to Kalymnos and sponge diving. Nowadays, it prevails occupational (aquaculture, underwater works), research (underwater archaeology), military training and touristic activities (recreational diving, diving tourism). Diving training (diving schools) has expanded accordingly.
Let’s take a closer look on the types of diving, on the basis of influence on the human body and physiology.
1. Free (or skin) diving: in this case, the person “travels” underwater without the use of a breathing device. This dive depends on the person’s physical status and endurance, lasting no more than a few minutes. It is also called breath-hold diving
2. Autonomous diving: in this case, a source of breathing gas is used by the person underwater. The diver has the autonomy to travel underwater using tanks of compressed gas (usually air). This way he has the ability to stay underwater as long as a couple of hours, depending on the depth and some other factors. This is what we call SCUBA diving (S.C.U.B.A.: Self-Contained Underwater Breathing Apparatus)
3. Diving when the source of breathing gas is on the surface and given to the diver through an air-line is, obviously, not autonomous. However, on the basis of human physiology and effects it has on the diver, we consider it the same type of diving
4. Submarines (and their crews) “dive” into various depths. However, pressure inside the submarine does not change, while external pressure (applied on the submarine’s hull) increases in proportion to the depth. As a result, submarine crews normally do not count as divers (unless, in the unfortunate case of damage of the pressure hull that leads to flooding and pressure increase-or during procedures for crew escape)
Diving (or Undersea) Medicine studies, treats and manages disorders resulting from autonomous diving (as well as other cases of exposure to non-diving pressure variations – caisson workers, subway construction etc). Inert gas bubbles and the resulting Decompression Illness (DCI) constitute the landmark of Diving Medicine, and in the vast majority of cases it originates from this type of diving. Rarely, breath-hold diving has been reported to lead to DCI, under certain extreme conditions, which are far from the average breath-hold diver’s performance. The basic difference is that the SCUBA diver stays and breathes underwater. For the most of the following text, the term diving will refer to autonomous diving.
Diving Medicine has evolved through the years in parallel with SCUBA diving development and nowadays, the average autonomous diver’s physical profile is very different from what it used to be a couple of decades ago. And although Decompression (hyperbaric) Chambers and use of Treatment Tables are still based on the same basic principles and philosophy, it’s the physical variability of people participating in recreational diving that makes this field of medicine increasingly interesting. Conditions that used to preclude someone from diving are now considered compatible with diving, either with limitations and precautions or not. Customization or even individualization of diving activities is now a possibility, following appropriate tests, specialist opinion and surveillance. We are aware now, of diving aspects that influence long-term health of an individual – of special interest for professional divers. Of course, health and safety first. Persons that should avoid this outstanding activity must be identified. Studying and examining conditions and symptoms that used to be answered by “problem” or “no problem” is not sufficient anymore. Appropriately informed diving training and plethora of diagnostic testing coupled with development of Diving Medicine specialization in Greece, give the ability of specialized consulting services that guide diagnostic & treatment strategy. The next step forward is augmentation of diving tourism. Presence of respective specialists is important to all the above-mentioned, as well as the very important part – prevention of diving incidents.