| eed to:- | Remedy | Comments |
| owspan="5"|Breathe underwater | Open-circuit scuba set | Easy to refill. Safer to use than a rebreather. |
| b>rebreather | Longer duration per weight of set, but needs more training to be safe. |
| b>Surface supplied diving | Mostly for work diving |
| b>Standard diving dress | Mostly for work diving. Mostly merely of historical interest now. |
| b>(Liquid breathing system) | (In the real world this is at the early experiment stage.
It should allow very deep diving when it is developed.) |
owspan="4"|See underwater.
Protect the eyes.
(Man's eyes cannot focus accurately
when directly submerged.) | Eyes-and-nose diving mask | Easy to clear if flooded. Easily knocked off. |
| b>Full face mask | Allows talking if no mouthpiece inside.
Difficult or impossible to go to snorkel on running out of air. |
| b>Diving helmet | As fullface mask. Protects the head well. |
| pecial contact lenses | Occasionally used by commando frogmen instead,
to avoid seachlight beams reflecting off a mask window. |
owspan="2"|Move faster than
with unequipped swimming | Fins on feet | Cheap, easy to use. Even without a diving suit, wetsuit bootees let the diver wear bigger fins. |
| b>Diver Propulsion Vehicles | Faster but expensive, and heavy and bulky to carry about on land. |
void hypothermia (losing
body heat to the water) | colspan="2"|In cool or cold water, wear an adequately warm diving suit for the conditions. Also, much heat can be lost from a head without a hood. |
| owspan="3"|Control buoyancy | Diving weighting systems | Usually a weight belt. Some breathing sets have built-in weight pouches. |
| a href="/encyclopedia/diving-suit" title="diving suit">diving suits | The buoyancy of most drysuits can be changed during the dive. |
| b>buoyancy compensators | These make diver's buoyancy control much easier. |
| rotect the skin from cuts and stings and grazes | Diving suits and diving gloves and diving suit bootees serve this purpose. | In very warm water try diving in a boiler suit, or other strong clothes with long sleeves and legs. |
| reathe from atmosphere to save air when on surface | snorkel | Advisable, despite some naval divers' opinions. |
| ypes of this sort of diving disorder, and how to avoid them |
| ype | Cause | How to avoid it |
| b>Drowning | Being unable to inhale anything but water | See under "anoxia" |
| b>Secondary drowning | Can occur hours after a near drowning | Prompt medical treatment after near drowning |
| b>Oxygen poisoning | Breathing gas with too much oxygen in | Proper training before using a rebreather. |
| owspan="2" |Hypoxia or anoxia while having gas to breathe, but with too little oxygen to support normal activities or consciousness. | This is a risk when using a rebreather | Keep rebreathers properly maintained.
Proper training before using a rebreather. |
| full cylinder standing for a long time while the inside of the cylinder rusts, using up oxygen in the contained air, before the diver uses the cylinder | Keep cylinders routinely checked and tested. If a cylinder has stood full for months, empty it and refill it. |
| owspan="5" |Anoxia due to having no gas to breathe | Equipment failure | Keep equipment routinely checked and in good condition |
| unning out of air due to poor dive discipline | Better training of divers. More disciplined attitude when underwater. |
| unning out of air due to getting trapped by nets | Better awareness underwater. Carry a diver's net cutter. |
| unning out of air due to getting trapped or lost in enclosed spaces underwater (e.g. caves and shipwrecks) | Better training and leadership for such types of diving. See cave diving and wreck diving. |
| unning out of air due to getting lost in open water | Better training and leadership, including in using a compass underwater |
| b>Salt water aspiration syndrome | Inhaling a mist of sea water from a faulty demand valve causing a reaction in the lungs | Keep equipment routinely checked and in good condition |
| owspan="2" |Carbon monoxide poisoning | Air cylinder filled by a compressor which sucked in its engine's (or another engine's) exhaust | Proper precautions when filling cylinders |
| il getting into the air feed and firing in the air compression cylinder, like in a diesel engine | Proper servicing of the compressor |
| b>Emphysema caused by inhaling oil mist | This happens gradually over a long time. This is a particular risk with a pumped surface air feed. | Use proper filters in the air pump or air compressor. |
| b>Carbon dioxide poisoning | The diver producing carbon dioxide faster than his rebreather's soda lime can absorb it | Keep rebreathers properly maintained.
Proper training before using a rebreather. |
| arious effects of breathing a wrong gas | A wrong gas was put in a cylinder | Check conditions where you have your cylinders refilled. Put the proper gas identification markings on cylinders. |
| ypes of this sort of diving disorder, and how to avoid them |
| ype | Cause | How to avoid it |
| owspan="2"|Eardrum damage. Cold water in the middle ear chills the inner ear, causing dizziness and disorientation etc. | Failing to equalize the pressure in the middle ear with surrounding pressure. | Do not dive if the eustachian tube is congested, e.g. with the common cold.
Proper diver training in clearing the ears. |
| he pressure in the outer ear not equalizing with surrounding pressure | Make sure that your hood does not make an airtight seal over the outside ear hole. |
| amage to other body air spaces, such as the paranasal sinuses. | Obstruction to the sinus ducts | Do not dive with conditions such as the common cold |
| queeze damage to bood vessels around the eyes | Caused by suction from the air space inside a mask which is not a fullface mask | Let air into the mask through the nose. Do not dive with eyes-only goggles. |
| queeze damage to skin under folds in a drysuit | Suction into the space inside the fold | Modern drysuits have a tube connection to inflate the drysuit from the cylinder |
| ung squeeze: blood in lungs | Extreme depth when snorkelling | Use an underwater breathing set |
| elmet squeeze, with the old standard diving dress. This does not happen with scuba where there is no solid pressure-tight helmet | A valve in the helmet failing. In severe cases much of the diver's body could be mangled and compacted inside the helmet | Keep equipment in good order and inspected. Proper training in its use. |
| ypes of this sort of diving disorder, and how to avoid them |
| ype | Cause | How to avoid it |
| a href="/encyclopedia/Pulmonary" title="Pulmonary">Pulmonary barotrauma: "burst lung" | Holding the breath while ascending | rowspan="6"|Never hold the
breath while diving
with breathing
apparatus |
| olspan="2" align="center"|This can cause: |
| b>Pneumothorax | Collapsed lung, air loose in the pleural cavity |
| b>Interstitial emphysema | Gas trapped in the chest after burst lung |
| b>Subcutaneous emphysema | Gas loose under the skin. |
| b>Gas embolism | Air or other gas in the blood stream.
Its effects can be very similar to decompression sickness. |
| ain in a sinus | Blockage of the sinus's duct | Do not dive with nasal congestion |
| ardrum bursting outwards | Blocked Eustachian tube | Do not dive with nasal congestion |
The term | ypes of this class of diving disorder, and how to avoid them. Click on each type to find its symptoms. |
| ype | Cause | How to avoid it |
| b>Hypothermia | Losing body heat to the water. Water carries heat away far better than air. | In cool or cold water, wear an adequately warm diving suit for the conditions. Also, much heat can be lost from a head without a hood. |
| uts, sometimes with coral tissue left in them | Coral | Do not get too close to coral. Avoid diving with bare skin. |
| uts | Rock, metal, etc | Avoid diving in bare skin, particularly in caves or shipwrecks. |
| tings | Fire coral | It is yellow. Learn to identify it. |
| tings, some dangerous | Some jellyfish | Learn about the dangerous species. Avoid diving with bare skin. |
| deep cut which leaves poison in the wound | sting ray (its self-defence reaction) | Do not poke about in sand where they live. Care when wading. |
| oison-injecting spines | lionfish, stonefish, crown of thorns starfish, some sea urchins in warm seas | Learn to identify them. Keep away from them. Care when wading. |
| oison injection | Blue ringed octopus, in parts of the Pacific Ocean | Learn to identify them. Keep away from them. |
| b>Shark bites | Sharks, in warm seas | Get proper information on them |
| b>Crocodile attack | Crocodiles, in some tropical waters | Get proper information on them |
| owspan="3"|Electrocution | Electric eel, in some South American fresh water | Get proper information on them |
| b>Electric ray, in some warm seas | Get proper information on them |
| t is said that some naval anti-frogman defences use electric shock | Keep out of armed forces areas |
| owerful ultrasound | It is said that some naval anti-frogman defences use powerful ultrasound. Also used for long-range communication with submarines | Keep out of armed forces areas. Avoid large ships' ordinary sonar. |
| xposure to disease carried by in-water organisms | Weil's disease (in rat's urine)
Bilharzia (in some warm fresh water)
Various bacteria found in sewage | In affected water, dive in watertight drysuit and full face diving mask |
| xposure to harmful chemicals in the water | May be found in water polluted by industrial waste outfalls | In affected water, dive in watertight drysuit and full face diving mask |
| roken bones, bleeding wounds and other trauma | Colliding with a boat or its propellor.
Wave action on the shore. | Use Surface detection aids or a diving shot to mark position. Plan a safe exit point and check weather and tidal conditions. |