Freediving terms

Here you find the most commonly used terms in freediving.

A.I.D.A.Association Internationale pour le
Développement de l’Apnée – one of the main international freediving agencies
aerobicCellular metabolism with oxygen,
requiring oxygen for breathing
air embolismObstruction of the circulatory
system caused by an air bubble as e.g.  as a complication from scuba diving [syn: aeroembolism] 2: pain
resulting from rapid change in pressure [syn: decompression sickness,
aeroembolism, caisson disease, bends]
anaerobicNot aerobic  –  not needing or without oxygen –  an activity in which the body incurs an oxygen debt
anaerobic metabolismCreation of energy through the
combustion of carbohydrates in the absence of oxygen.

This occurs when the lungs cannot
put enough oxygen into the bloodstream to keep up with the demands from the
muscles energy. Generally  used
for short busts of activity

apneaFrom the Greek, it means
“without, or not breathing”.
ascent boBlacking out while ascending from
a dive, if it happens, it’s usually in the last 10 – 15 meters
ascent ratesSpeed at which one ascends from a
barotraumasAn injury that results due to
rapid or extreme changes in pressure.
bi-finsTraditional swimming fins – one
for each foot
blackoutLosing consciousness during
breath-hold activities
blood pHLevel of acidity/alkalinity in the
blood shiftRelated to the mammalian diving
reflex – to prevent collapse under great pressure, the wall of the lungs fill
with blood from other parts of the body.
boSee: Blackout
bottom timeTime spent underwater during a
dive while freediving, or the time spent lingering at the bottomweight/plate
bradycardiaPart of the mammalian diving
reflex: Slowing down of the heart rate and pulse
breathing oxygenBreathing pure oxygen as a
therapeutic measure or as a preparation for increasing one’s time underwater.
breath-upSet of breathing procedures done
before a long immersion – used to build up the capacity of the body in order
to spend more time underwater on a single breath.
carp breathingSee: Packing
certifying agenciesOfficial freediving agencies that
have the authority to certify the different local, national and world
freediving records.
clogged earHaving the ear canal of the outer
ear obstructed, also called swimmers ear.
CMASCMAS is an international
organisation to promote SCUBA diving and other underwater sports. Founded by
J.Y. Cousteau
CO2 narcosisToxicity resulting from too high
levels of carbon dioxide in the blood
CO2 toleranceTolerance to carbon dioxide in the
collapsed lungA collapsed lung, or pneumothorax,
involves the collapse of the tissues of part or all of one lung so that
oxygen cannot be absorbed into the blood stream in the normal way. Changes in
pressure during diving may cause tissue damage. See also: pneumothorax
constant ballastSee: Constant weight
constant weightOne of the freediving disciplines:
Diving down as deep as one can and ascending without the use of any
mechanical device and rope. The weight of the freediver must remain the same
during descent and ascent.
contractionsAfter a certain time without
sufficient oxygen, the diaphragm starts to flutter and also experience
contractions in order to “remind” the body that it needs to breath.
countdown timeThe time just prior to a dive or
static apnea. It is usually called out in a competition to help freedivers
time their preparation and breath-up prior to the dive.
crampsA sudden and involuntary
tightening of a muscle – usually can be quite painful. Cramps usually happen
in the legs for swimmers and freedivers.
Crazy CubanDiving as deep as possible with no
aids whatsoever – no mask, fins, or weight belt. Also favoured by the
freediver Sebastian Murat.
DCISee: decompression sickness.
Acronym for Decompression Illness
DCSSee: decompression sickness
decompressionProcedure used by scuba divers to
reabsorb the nitrogen that has built up in the blood stream during long and
deep dives
decompression chamberA pressurized chamber used to
reproduce the pressures found at great depths. Usually used to help divers
recover from decompression sickness.
decompression sicknessPhysiological disorder caused by a
rapid decrease in atmospheric pressure, resulting in the release of nitrogen
bubbles into the body tissues. It is also known as caisson disease, altitude
sickness, and the bends
DEMA Dive ShowDiving Equipment & Marketing
Association – Trade fair organization
depth adaptationThe capacity of the lungs to adapt
to the pressure found at great depths.
dive computersComputer that can measure the
depth and time spent at each depth. It also calculates the recommended
decompression times needed by the diver.
diving responseLowering of the heart rate and
constriction of the blood vessels in the body causing blood to be redirected
to the brain and heart to keep the important vital functions active.
dizzinessDisorientation of the sense of
balance – vertigo.
dry staticStatic apnea on dry land.
dynamic apnea (with fins)One of the disciplines of  freediving: swimming underwater as
far as one can with fins.
dynamic apnea (without fins)One of the disciplines of  freediving: swimming underwater as
far as one can without any type of fins.
ear jammingWhen the Eustachian Tubes close
and no amount of pressure seems to open them during a dive
embolismSee: Air embolism
empty lung divesRefers to “negative pressure
dives” where freedivers prepare their lungs for very deep dives by
emptying them of air and diving several meters. The lack of air pressure in
the lungs simulates diving to a much greater depth and is useful as a warm up
equalizationBalancing the air pressure in the
middle and outer ear.
equalizeThe act of equalizing the pressure
difference between the middle and outer ear. There are several techniques.
The two main ones are the Valsalva and the Frenzel techniques.
Eustachian tubeA tube that connects the middle
ear with the nasopharynx and permits the equalization of pressure on both
sides of the eardrum. It is bony and cartilaginous.
F.R.E.E.Freediving Regulations &
Education Entity – Freediving teaching agency, less active
failure depth, breakpointThe depth where lung pressure
turns negative and below that it is difficult -or impossible- to bring air in
the mouth for equalization
fire breathingSlow shallow breathing, slowed by half closing
epiglottis. The idea is to keep a nearly continuous ‘greater-than-ambient’
pressure in the lungs.
fluid gogglesDiving mask containing liquid
instead if air to avoid using up valuable air equalizing the mask at depth.
May have corrective lenses to adjust for the liquid the eyes have to see
free ascent dangersThe dangers of ascent, could be
decompression sickness (rare in freedivers), shallow water blackout (most
common danger), and overstretching of the lungs after having packed allot.
(Also very rare)
free immersionOne of the disciplines of
freediving: diving as deeply as one can without fins and pulling one’s self
down and up a guide rope.
freedivingThe fine art of diving without
using any breathing apparatus. Freediving can be competitive or recreational.
Frenzel TechniqueEqualization technique involving
using the tongue as a piston to force air through the Eustachian Tubes.
haemoglobinProtein in the red blood cells
which combines with and carries oxygen around the body, and gives blood its
red colour
heavy packingPacking allot of air into the
lungs – some freedivers can pack up to 4 liters of extra air into their
HMS DolphinA special 30 meter deep swimming
pool in the UK designed for training submariners to escape from a submarine
at 30 meters on a single breath. Freedivers can also use the HMS Dolphin
paying a fee.
hook breathingTaking a deep breath after a long
breath–hold and bearing down on it for a couple of seconds to speed up the
transfer of oxygen from the lungs to the rest of the body as well as to force
blood up to the head and keep the O2 moving.
hyperbaric chamberA pressurised chamber that allows
for the delivery of oxygen in higher concentrations for therapeutic benefit –
useful for decompression illness
hyperbaric oxygen therapyThe therapeutic intermittent
administration of oxygen in a chamber at greater than sea-level atmospheric
pressures (three atmospheres). It is considered effective treatment for air
and gas embolisms as well as for decompression illness.
hypercapniaToo much carbon dioxide in the
hyperoxiaToo much oxygen in the blood
hyperventilationHyperventilation is the practice
of excessive breathing with an increase in the rate of respiration or an
increase in the depth of respiration, or both
hypocapniaLower than normal carbon dioxide
in the blood stream, can result from hyperventilation and bring on blackout
sooner than normal.
hypothermiaWhen a person’s body temperature
falls below normal due to exposure to extreme cold. This is a dangerous
condition that can result in death.
hypothermic diving systemSystem devised by Eric Fattah
taking advantage of steep thermoclines to induce hypothermia therefore
increasing the diving reflex to be able to dive deeper.
hypoxemiaLower than normal oxygen in
arterial blood which gives rise to hypoxia.
hypoxiaLower than normal oxygen supply to
tissues even though there might be a proper amount of blood in the tissues.
IAFDInternational Association of Free
Divers – Freediving teaching Agency, less active
lactic acidLactic acid is a by-product of
anaerobic glycolysis and anaerobic metabolism. Although used as a fuel by the
heart, excessive lactic acid slows down contractions of the skeletal muscles,
preventing you from walking fast
LMCLoss of Motor Control – also known
as “samba”. It occurs when the muscles have almost no oxygen and
suffer seizures. It happens just before blackout.
lung fluidFluid i.e. plasma filling the
walls (alveolis) of  your lungs
is a response to the increased pressure at depth (usually at around 50m but
it can vary quite a bit depending how much air you have in your lungs and
your residual volume) to protect your lungs and other organs.
Lung packingSee: Packing
lung squeezeSee: pulmonary edema.
lung trainingTraining the lung to have more
strength and capacity
lung volumeAmount of air in the lungs, also
known as TLC
mammalian diving reflexSee: diving response
mask airThe amount of air in the mask.
There are high–volume and low–volume masks. Freedivers prefer low–volume air
as they are easier to equalize.
mask pumpingTechnique for utilizing the air in
one’s mask during ascent. See: rebreathing
mask volumeSee: Mask air
Middle-Ear BarotraumaMiddle–Ear problems due to quick
changes in pressure. It can happen on ascent when the pressure in the outer
ear diminishes faster than in the inner ear. Also known as “reverse
monofinsFins based on the design of a
dolphin’s tail. Both feet fit into a single monofin. Even though hard to use
at first, they provide greater power and speed than bi–fins.
N2 narcosisSee: nitrogen narcosis
narcosisSee: nitrogen narcosis
negative pressure divesSee: Empty lung dives
newbieSomeone new to a particular
activity, a beginner
nitrogen narcosisMental state similar to euphoria,
drunkenness and disorientation caused by the narcotic effects of the air’s
nitrogen at high pressure. Divers often exhibit dangerous behaviour such as
ditching equipment underwater. Also known as rapture of the deep.
no limitsOne of the disciplines of
freediving: Descending as far as possible with ballast equipment (usually a
sled) and ascending with an air balloon or similar.
nose clipDevice that closes the nostrils to
prevent water getting in or air getting out.
O2 levelsLevels of oxygen in the blood
oxygen narcosisSee: oxygen toxicity
oxygen toxicityOccurs when one breathes high
partial levels of oxygen in the blood stream. Symptoms can be deep fatigue
while breathing, muscular twitching, anxiety, confusion, incoordination, and
convulsions including visual and auditive abnormalities
pack stretchingStretching of the lungs due to
packingSpecial techniques for filling the
lungs with more air than normally possible.
PaCO2Partial pressure of arterial
carbon dioxide in the blood
PBAcronym for “Personal
peripheral vasoconstrictionIt has been shown that at depth,
blood flow is shunted from the limbs to those organs whose oxygen consumption
is critical, the heart and brain
personal bestsOne’s best record in any of the
disciplines of freediving
pipe maskDiving mask with a small tube
extending from the mask to mouth for equalizing.
pneumothoraxA condition in which air or other
gas is present in the pleural cavity and which occurs spontaneously as a
result of disease or injury of lung tissue or puncture of the chest wall or
is induced as a therapeutic measure to collapse the lung. See also: Collapsed
PowerlungTraining instrument used for
enhancing lung capacity.
pranayamaYogic breathing techniques for
balancing and enhancing the body’s vital energies.
pulmonary edemaDangerous medical condition where
the lung fills with increased interstitial fluid causing the alveoli to flood
with the fluid and be coated in blood, thus reducing the alveoli’s capacity
to transfer oxygen.
rebreathingIn relation to freediving: Sniffing
or rebreathing the expanding air in one’s mask while ascending. Also known as
“mask pumping”
recreational freedivingFreediving for pure and simple
residual lung volume (RV)The volume of air that remains in
the lungs after exhaling completely
Reverse SqueezeSee: Middle–Ear Barotrama
RVSee: Residual lung volume
S.A.F.E.R.“Specialized Advanced
Freediving Enhancement & Reliability ” –  Freediving teaching agency, less active
sambaLoss of muscle control commonly
known as “samba”,  preceding
blackout in many cases.
SaO2Saturation of Oxygen (arterial
security ropeGuide rope or line used to orient
the freediver while descending, also known as the rope or the diverope.
shallow water blackoutSudden loss of consciousness
caused by pressure drop in oxygen.
skindivingSwimming underwater or on the
surface usually with the help of a face mask, fins, and a snorkel
solo freedivingFreediving alone without a buddy
spirometerMedical instrument used to measure
vital lung capacity
spottingHaving a buddy watch you for
safety reasons while engaging in freediving activities either in the swimming
pool or the sea.
static apneaOne of the disciplines of
freediving: Seeing how long one can hold one’s breath while floating on the
surface with the face submerged.
suit squeeze“Suit squeeze”, where
the hood of a stretchy wetsuit ‘seals’ around the outer ear, trapping air in
the outer ear. This can cause problems due to incorrect equalizing on descent
or ascent.
surface intervalsTime spent at the surface between
SWBSee: Shallow water blackout
tear duct equalizationEqualization (of the mask?)
through the tear ducts
tidal volumeThe volume of air normally inhaled
or exhaled when one is making no extra effort.
TLCSee:Total Lung Capacity
total lung capacity (TLC)Total Lung Volume: The sum of RV
and VC
variable ballastOne of the freediving disciplines:
Going down with a weighted device and coming up pulling on a rope or swimming
vasoconstrictionSee: peripheral vasoconstriction
VCSee: Vital Capacity
ventilationMore than normal breathing, less
than hyperventilation.
vital capacity (VC)The amount of air of a complete
and full exhalation including the expiratory reserve volume
warm upsPreparative exercises previous to
an activity requiring great physical effort. Usually different kind of dives.
weight belt ditchingReleasing the weight belt
weightingApplying the correct amount of
weight for one’s freediving or scuba needs
weightsUsually lead weights used for
counteracting the body’s (and wetsuit’s) natural buoyancy.
wet lungAlso known as Pulmonary Edema: The
abnormal accumulation of liquids in the lungs due to rapid changes in
pressure. Different from lung fluid, this is harmful and can lead to
secondary drowning.
wet staticsStatic apnea in the pool or sea