Diving suit - AbsoluteAstronomy.com

A diving suit is a garment or device designed to protect a diver from the underwater

Underwater

Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...

environment. A diving suit typically also incorporates an air-supply (ie SCUBA

Scuba

Scuba is an acronym for self-contained underwater breathing apparatus. It may also refer to:* Scuba diving, the use of a self-contained breathing set to stay underwater for periods of time* Scuba set, the equipment used to do scuba diving...

or pressurised air hose).

History

The first diving suits were Standard diving dress

Standard diving dress

A standard diving dress consists of a metallic diving helmet, an airline or hose from a surface supplied diving air pump, a canvas diving suit, diving knife and boots...

es, which could be described nowadays as a ambient pressure diving suit, and were made out of a metallic diving helmet, a canvas diving suit, diving knife and boots. It has now been rendered obsolete.

Diving suits made of rubber

Rubber

Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

were first used in World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

by Italian frogmen who found them indispensable in their use. They were made by Pirelli

Pirelli

Pirelli & C. SpA is a diverse multinational company based in Milan, Italy. The company, the world’s fifth largest tyre manufacturer, is present in over 160 countries, has 20 manufacturing sites around the world and a network of around 10,000 distributors and retailers.Founded in Milan in 1872,...

and patented in 1951.

Modern diving suits can be divided into two kinds:

"soft" or ambient pressure
Ambient pressure
The ambient pressure on an object is the pressure of the surrounding medium, such as a gas or liquid, which comes into contact with the object....

diving suits - examples are wetsuit
Wetsuit
A wetsuit is a garment, usually made of foamed neoprene, which is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports, providing thermal insulation, abrasion resistance and buoyancy. The insulation properties depend on bubbles of gas enclosed within the material,...

s, dry suit
Dry suit
A dry suit or drysuit provides thermal insulation or passive thermal protection to the wearer while immersed in water, and is worn by divers, boaters, water sports enthusiasts, and others who work or play in or near cold water. A dry suit normally protects the whole body except the head, hands, and...

s, semi-dry suits and dive skins
"hard" or atmospheric pressure diving suits
Atmospheric diving suit
An atmospheric diving suit or ADS is a small one-man articulated submersible of anthropomorphic form which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere...

- an armored suit that permits a diver to remain at atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

whilst operating at depth where the water pressure is high.

Dive skins

Dive skins are used when diving in water temperatures above 25 °C (77 °F). They are made from Spandex

Spandex

Spandex or elastane is a synthetic fibre known for its exceptional elasticity. It is strong, but less durable than natural Latex, its major non-synthetic competitor. It is a polyurethane-polyurea copolymer that was co-invented in 1959 by chemists C. L. Sandquist and Joseph Shivers at DuPont's...

or Lycra and provide little thermal protection, but do protect the skin from jellyfish

Jellyfish

Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...

stings, abrasion and sunburn

Sunburn

A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...

. This kind of suit is also known as a 'Stinger Suit'. Some divers wear a dive skin under a wetsuit, which allows easier donning and (for those who experience skin problems from neoprene) provides additional comfort.

Wetsuits

Wetsuits are relatively inexpensive, simple, Neoprene

Neoprene

Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene in general has good chemical stability, and maintains flexibility over a wide temperature range...

suits that are typically used where the water temperature is between 10 and 25 °C (50 and 77 F). The foamed neoprene of the suit thermally insulates the wearer. Although water can enter the suit, a tight fitting suit prevents excessive heat loss because little of the water warmed inside the suit escapes from the suit.

Proper fit is critical for warmth. A suit that is too loose will allow too much water to circulate over the diver's skin, robbing body heat. A suit that is too tight is very uncomfortable and can impair circulation at the neck, a very dangerous condition which can cause blackouts. For this reason, many divers choose to have wetsuits custom-tailored instead of buying them "off-the-rack." Many companies offer this service and the cost is often comparable to an off-the-rack suit.

Wetsuits are limited in their ability to provide warmth by two factors: the wearer is still exposed to some amount of water, and the insulating Neoprene can only be made to a certain thickness before it becomes impractical to don and wear. The thickest commercially-available wetsuits are usually 10mm thick. Other common thicknesses are 7mm, 5mm, 3mm, and 1mm. A 1mm suit provides very little warmth and is usually considered a dive skin, rather than a wetsuit.

Semi-dry suits

Semi-dry suits are effectively a thick wetsuit with better-than-usual seals at wrist, neck and ankles. They are used typically where the water temperature is between 10 and 20 °C (50 and 68 F). The seals limit the volume of water entering and leaving the suit. The wearer gets wet in a semi-dry suit but the water that enters is soon warmed up and does not leave the suit readily, so the wearer remains warm. The trapped layer of water does not add to the suit's insulating ability. Any residual water circulation past the seals still causes heat loss. But semi-dry suits are cheap and simple compared to dry suits. They are made from thick Neoprene, which provides good thermal protection. They lose buoyancy and thermal protection as the trapped gas bubbles in the Neoprene compress at depth. Semi-dry suits can come in various configurations including a single piece or two pieces, made of 'long johns' and a separate 'jacket'. Semi dry suits do not usually include boots, so a separate pair of insulating boots are worn.

Drysuits

Drysuits are used typically where the water temperature is between -2 C. Water is prevented from entering the suit by seals at the neck and wrists; also, the means of getting the suit on and off (typically a zipper

Zipper

A zipper is a commonly used device for temporarily joining two edges of fabric...

) is waterproof. The suit insulates the wearer in one of two main ways: by maintaining pockets of air between the body and the cold water in standard air-containing fabric undergarments beneath the suit (in exactly the way that insulation garments work in air) or via (additional) foamed-neoprene material which contains insulative air, which may be incorporated into the outside of the drysuit itself.

Both fabric and neoprene drysuits have advantages and disadvantages: a fabric drysuit is more adaptable to varying water temperatures because different garments can be layered underneath. However, they are quite bulky and this causes increased drag and swimming effort. Additionally, if a fabric drysuit malfunctions and floods, it loses nearly all of its insulating properties. Neoprene drysuits are comparatively streamlined like wetsuits, but generally do not allow garments to be layered underneath and are thus less adaptable to varying temperatures. An advantage of this design is that even it if floods completely, it essentially becomes a wetsuit and will still provide a degree of insulation.

Special drysuits (typically made of thick rubber) are worn by commercial divers who work in contaminated environments such as sewage or hazardous chemicals. The drysuit is sealed to a diving helmet

Diving helmet

Diving helmets are worn mainly by professional divers engaged in surface supplied diving, though many models can be adapted for use with scuba equipment....

to prevent any exposure to the hazardous material.

For additional warmth, some drysuit users inflate their suits with argon

Argon

Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...

, an inert gas which has superior thermal insulating properties compared to air. The argon is carried in a small cylinder, separate from the diver's breathing gas

Breathing gas

Breathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...

Hot water suits

Hot water suits are used in cold water commercial

Commercial Diving

Professional diving is a type of diving where the divers are paid for their work. There are several branches of professional diving, the most well known of which is probably commercial diving...

surface supplied diving

Surface supplied diving

Surface supplied diving refers to divers using equipment supplied with breathing gas using a diver's umbilical from the surface, either from the shore or from a diving support vessel sometimes indirectly via a diving bell...

. An insulated pipe in the umbilical line, which links the diver to the surface support, carries the hot water from a heater on the surface down to the suit. The diver controls the flow rate of the water from a valve near his waist, allowing him to vary the warmth of the suit in response to changes in environmental conditions and workload. Pipes inside the suit transport the water to the limbs, chest, and back. Special boots, gloves, and hood are worn. These suits are normally made of foamed neoprene

Neoprene

and are similar to wetsuits in construction and appearance, but they do not fit as closely by design. The wrists and ankles of the suit are open, allowing water to flush out of the suit as it is replenished with fresh hot water from the surface.

Hot water suits are often employed for extremely deep dives when breathing mixes containing helium are used. Helium conducts heat much more efficiently than air, which means that the diver will lose large quantities of body heat through the lungs when breathing it. This fact compounds the risk of hypothermia already present in the cold temperatures found at these depths. Under these conditions a hot water suit is a matter of survival, not comfort. Just as an emergency backup source of breathing gas is required, a backup water heater is also an essential precaution whenever dive conditions warrant a hot water suit. If the heater fails and a backup unit cannot be immediately brought online, a diver in the coldest conditions can die within minutes; depending on decompression obligations, bringing the diver directly to the surface could prove equally deadly.

Ambient pressure suits

There are five main types of ambient pressure diving suits

dive skins
wetsuits
semi-dry suits
drysuits
hot water suits

Apart from hot water suits, these types of suit are not exclusively used by divers but are often used for thermal protection by people engaged in other water sports activities such as surfing

Surfing

Surfing' is a surface water sport in which the surfer rides a surfboard on the crest and face of a wave which is carrying the surfer towards the shore...

, sailing

Sailing

Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

, powerboating

Powerboating

Power boating describes activities performed in a motorized boat. Generally, a power boat has a high power-to-weight ratio and a hull design that allows for easy planing, which allows for higher speed and improved handling. Also, the shape of the actual boat is usually very streamlined, which...

, windsurfing

Windsurfing

Windsurfing or sailboarding is a surface water sport that combines elements of surfing and sailing. It consists of a board usually two to four metres long, powered by the orthogonal effect of the wind on a sail. The rig is connected to the board by a free-rotating universal joint and comprises a...

, kite surfing, waterskiing, caving

Caving

Caving—also occasionally known as spelunking in the United States and potholing in the United Kingdom—is the recreational pastime of exploring wild cave systems...

and swimming.

Ambient pressure suits are a form of exposure protection protecting the wearer from the cold

Hypothermia

Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...

. They also provide some defence from abrasive and sharp objects as well as potentially harmful underwater life. They do not protect divers from the pressure of the surrounding water or resulting barotrauma

Barotrauma

Barotrauma is physical damage to body tissues caused by a difference in pressure between an air space inside or beside the body and the surrounding fluid...

and decompression sickness

Decompression sickness

Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...

.

The suits are often made from Neoprene

Neoprene

, heavy-duty fabric coated with rubber

Rubber

, or PVC

Polyvinyl chloride

Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...

.

Added buoyancy

Buoyancy

In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

, created by the volume of the suit, is a side effect of diving suits. Sometimes a weightbelt

Diving weighting system

Divers wear weighting systems, weight belts or weights, generally made of lead, to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders...

must be worn to counteract this buoyancy. Some drysuits have controls allowing the suit to be inflated to reduce "squeeze" caused by increasing pressure; they also have vents allowing the excess air to be removed from the suit on ascent.

Diving suit combinations

A "shortie" wetsuit may be worn over a full wetsuit for added warmth. A "skin" may also be worn under a wetsuit. This practice started with divers (of both sexes) wearing women's body tights under a wetsuit for extra warmth and to make donning and removing the wetsuit easier. A "skin" may also be used instead of an undersuit beneath a drysuit in temperatures where a full undersuit is not necessary.

External links

Experimental Dive Suit Flies Navy Divers Where None Have Gone Before - Development of a 1-atmosphere diving suit.
Scuba America Historical Center - The development of the first wetsuit.
LA Times: Surfing whodunit - The history of the wetsuit.
Wetsuit Guide
Diving Equipment Guide
ADS database

History of Diving Museum

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

History

Dive skins

Wetsuits

Semi-dry suits

Drysuits

Hot water suits

Ambient pressure suits

Diving suit combinations

See also

External links