Things You Need to Know About Scuba Diving

Scuba diving is a one of a kind sport. You are in a new and exciting environment, going where nature did not intend homosapiens to venture. Scuba diving’s uniqueness throws up an interesting set of problems for the human body and scuba divers have come up with novel ways of surmounting these. Let’s take a look at some of the vital things that everyone needs to know before going scuba diving.

Breathing Underwater

Early on, scuba divers discovered it was not enough to simply breathe air when diving at depth. There is also the problem of ambient pressure (the pressure acting on a diver wherever he is) which compresses the lungs and chest, making it difficult to breathe. It is the weight of water above you that increases the pressure as you descend in depth. Demand valve regulators are able to measure the ambient pressure and supply the diver with oxygen at exactly the same pressure, making it easy for the diver to breathe.

Normal air is 21% oxygen, 78% nitrogen and 1% other gases. While this is suitable for most scuba diving, extra deep dives require different gas mixtures. Nitrox is one such gas. It has less nitrogen in order to reduce the build up of nitrogen in the blood stream which can lead to nitrogen narcosis or the bends.

Diving Gas Dangers

The behaviour of gases inside the human body changes at extreme pressures. As a result, there are four dangers that every scuba diver must be aware of when thinking about breathing underwater.

Nitrogen Narcosis

Nitrogen narcosis can occur at any depth but is most likely when diving at 30 metres and below. It is hard to recognise but its effects can be deadly. If affected, a diver will start behaving irrationally and foolishly. In a fashion similar to being drunk, scuba divers may at first feel relaxed and in control of their immediate environment when in fact being oblivious to looming danger. In extreme cases, divers can be stricken with exhausting paranoia, too scared to move from where they are. The precise effects of nitrogen narcosis depend on the scuba diver involved, their personal history and the depth of the dive.

The good news is that it is easily curable by returning to shallower depths for a few minutes. However, in more advanced diving, in wrecks, caves or at great depth this may not be immediately possible, so divers must be extra vigilant. Tests have proven that all divers are susceptible to nitrogen narcosis to some degree, though many learn to control it or are aware of its effects. Acclimatisation, proper training and abstinence from drink and drugs in the period before a dive are thought to reduce the likelihood of suffering an attack.

Decompression Sickness

Decompression sickness is popularly known as the bends and it happens in scuba diving when a diver ascends from depth too rapidly. Nitrogen and other inert gas bubbles form in the blood stream. This causes pain in the joints and articulations with the shoulders being most commonly affected.

Severe cases of the bends can cause death due to inert gas bubbles restricting the flow of blood to the brain. For this reason, when diving at depth scuba divers must make decompression stops on their ascent to the surface. These decompression stops allow the nitrogen in the blood stream to be slowly diffused into the lungs and breathed out as normal.

With careful planning it is easy to avoid decompression sickness. When divers are operating at extreme depths, oil-rig workers for example, they must spend large amounts of time in a decompression chamber before they can return to the surface. The treatment for decompression sickness ranges from administering oxygen in minor cases, to a stint in a hyperbaric chamber for more serious cases.

Oxygen Toxicity

Contrary to what you may think, too much oxygen can be a bad thing for your health. Oxygen toxicity occurs when breathing a high concentration of the gas while under high pressure, during deep dives for example.

Oxygen toxicity is particularly dangerous because, unlike other gases (such as carbon dioxide), the body has no way of detecting when too much oxygen is present in the body. It is not completely understood why, but in severe cases oxygen toxicity causes convulsions in the scuba diver, making him likely to lose his air source and drown. Careful planning is all it takes to avoid oxygen toxicity, a scuba diver must never exceed the depth limit for the type of gas mix he is using.

Gases expand under less pressure

Never hold your breath while scuba diving, it only causes you to need more oxygen in the long run. If you ascend rapidly with a lung full of air it can expand thereby exploding your lungs and ending in an agonising death. It is a simple rule to follow. Never hold your breath, especially while ascending.

Underwater exposure

It is crucial that a diver is kept warm during his time spent underwater. Water conducts heat away from the skin at 25 times the normal rate. An unprotected scuba diver can suffer hypothermia, even in water that does not seem cold. The lack of continuous arm movement (a scuba diver uses his flippers to move) means that less blood will be circulating round the body and less body heat produced than when swimming normally. Therefore a diver may need a wetsuit even when he feels comfortable in the water at first.

Hypothermia can be deadly when diving as it results in loss of judgement and manual dexterity. This could be deadly in an emergency situation, for example if a diver is trying to cut himself free of an ensnaring line and cannot handle his dive knife. In very cold waters, drysuits, hoods, neoprene gloves and boots may be used.

Respect Marine Life

Wetsuits give the added benefit of protecting a scuba diver against abrasions and cuts while underwater. Luckily the UK is lacking in seriously dangerous marine life, although Portuguese Man o’ War can be deadly as they drift over from warmer climes.

Scuba divers should avoid stepping on, or touching marine life, particularly as some have very painful spikes and stings. The weever fish lies buried in sand and injects its poison into the feet of the unsuspecting or clumsy. Likewise, abalone can lodge their spikes in your foot, even through a sturdy flipper!

It is a rule of scuba diving that you must respect the sea and everything that lives in it. Even if it is not dangerous, avoid interfering with it. Fish are covered in a protective covering that can be wiped away by human touch. Likewise you should not remove objects from the sea bed, especially corals. Trophy hunting only detracts from the enjoyment of future scuba divers and if everyone took from a popular spot, soon there would be nothing left to see.