A diving suit is a garment or device designed to protect a diver from the
underwater environment. A diving suit may also incorporate a breathing gas
supply. but in most cases applies only to the environmental protective covering
worn by the diver. The breathing gas supply is usually referred to
separately. There is no generic term for the combination of suit and breathing
apparatus alone. It is generally referred to as diving equipment or dive
gear along with any other equipment necessary for the dive.
History The first diving dress designs appeared
in the early 18th century. Two English inventors developed the first
pressure-proof diving suits in the 1710s. John Lethbridge built a
completely enclosed suit to aid in salvage work. It consisted of a
pressure-proof air-filled barrel with a glass viewing hole and two watertight
enclosed sleeves. This suit gave the diver more maneouverability to
accomplish useful underwater salvage work.
After testing this machine in his garden pond Lethbridge dived on a number of
wrecks: four English men-of-war, one East Indiaman, two Spanish galleons and
a number of galleys. He became very wealthy as a result of his salvages. One
of his better-known recoveries was on the Dutch Slot ter Hooge, which had sunk
off Madeira with over three tons of silver on board.
At the same time, Andrew Becker created a leather-covered diving suit with a
helmet featuring a window. Becker used a system of tubes for inhaling and
exhaling, and demonstrated his suit in the River Thames, London, during which
he remained submerged for an hour. German-born British engineer Augustus
Siebe developed the standard diving dress in the 1830s. Expanding on
improvements already made by another engineer, George Edwards, Siebe produced
his own design - a helmet fitted to a full length watertight canvas diving
suit. Later dresses were made with waterproofed canvas invented by Charles
Mackintosh. From the late 1800s and throughout most of the 20th century,
most Standard Dresses consisted of a solid sheet of rubber between layers of
tan twill. Diving suits made of rubber were used in
World War II by Italian frogmen who found them indispensable in their use.
They were made by Pirelli and patented in 1951.
Modern diving suits Modern diving suits can be divided into
two kinds: "soft" or ambient pressure diving suits
- examples are wetsuits, dry suits, semi-dry suits and dive skins
"hard" or atmospheric pressure diving suits - an armored suit that permits a
diver to remain at atmospheric pressure whilst operating at depth where the
water pressure is high. = Ambient pressure suits =
Ambient pressure suits are a form of exposure protection protecting the
wearer from the cold. 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 and decompression sickness. 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, sailing, powerboating, windsurfing, kite
surfing, waterskiing, caving and swimming.
The suits are often made from Neoprene, heavy-duty fabric coated with rubber, or
PVC. Added buoyancy, created by the volume of
the suit, is a side effect of diving suits. Sometimes a weightbelt 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.
Dive skins Dive skins are used when diving in water
temperatures above 25 °C. They are made from spandex or Lycra and provide little
thermal protection, but do protect the skin from jellyfish stings, abrasion and
sunburn. 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 provides additional
comfort. The "Dive Skin" was originally invented
to protect scuba divers in Queensland Australia against the "Box" jellyfish
In 1978, Tony Farmer was a swimsuit designer and manufacturer who owned a
business called "Daring Designs". Besides swimwear he also did underwear
and aerobic wear which included a full suit in Lycra/Spandex. He became a scuba
diver and that was the catalyst to the invention of the "dive skin" as we know
it today. The "Surf Life Savers" in Queensland
used to wear 2nd hand panty hose as protection during the "box" jellyfish
season. The nematocysts of the jellyfish are so small that a thin layer of panty
hose is enough to prevent the stinger from penetrating deep enough into the
epidermis to get the venom into the blood stream. Tony thought this was a
little embarrassing for these 'bronzed' Aussies to be wearing on the beach and
thought that his one-piece Lycra suit would be far more suitable and
effective. Wetsuits
Wetsuits are relatively inexpensive, simple, Neoprene suits that are
typically used where the water temperature is between 10 and 25 °C. The
foamed neoprene of the suit thermally insulates the wearer. Although water can
enter the suit, a close fitting suit prevents excessive heat loss because
little of the water warmed inside the suit escapes from the suit to be
replaced by cold water, a process referred to as "flushing".
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 10 mm thick. Other common thicknesses are 7
mm, 5 mm, 3 mm, and 1 mm. A 1 mm 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. 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 are made 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 or gloves, so a separate pair of neoprene insulating boots and gloves are
worn. Drysuits
Drysuits are used typically where the water temperature is between −2 and 15
°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 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 or via 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 in some cases do not allow garments
to be layered underneath and are thus less adaptable to varying temperatures.
An advantage of this construction is that even it if floods completely, it
essentially becomes a wetsuit and will still provide a degree of insulation.
Special drysuits are worn by commercial divers who work in contaminated
environments such as sewage or hazardous chemicals. The drysuit has integral
boots and is sealed to a diving helmet and dry gloves to prevent any exposure
to the hazardous material. For additional warmth, some drysuit
users inflate their suits with argon, 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. This arrangement is
frequently used when the breathing gas contains helium, which is a very poor
insulator in comparison with other breathing gases.
Hot water suits Hot water suits are used in cold water
commercial surface supplied diving. 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 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. Heated water in the suit forms an active
insulation barrier to heat loss, but the temperature must be regulated within
fairly close limits. If the temperature falls below about 32°C, hypothermia can
result, and temperatures above 45°C can cause burn injury to the diver. The
diver may not notice a gradual change in inlet temperature, and in the early
stages of hypo- or hyperthermia, may not notice the deteriorating condition.
The suit is loose fitting to allow unimpeded water flow. This causes a
large volume of water to be held in the suit, which can impede swimming due to
the added inertia. When controlled correctly, the hot water
suit is safe, comfortable and effective, and allows the diver adequate control of
thermal protection, however hot water supply failure can be life-threatening.
Diving suit combinations A "shortie" wetsuit may be worn over a
full wetsuit for added warmth. Some vendors sell a very similar item and
refer to it as a 'core warmer' when worn over another wetsuit. A "skin" may also
be worn under a wetsuit. This practice started with divers 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.
= Atmospheric diving suits = An atmospheric diving suit 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.
These can be used for very deep dives for long periods without the need for
decompression, and eliminate the majority of physiological dangers
associated with deep diving. Divers do not even need to be skilled swimmers.
Mobility and dexterity are usually restricted by mechanical constraints,
and the ergonomics of movement are problematic.
See also Timeline of underwater technology
Space suit Standard diving dress
Atmospheric diving suit References
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