Understanding the scuba divers code….

by   Profile Cat   When 30th June 2016
S = Split Fins
lazy shot
L = Lazy Shot
O = Octopus

There is nothing more frustrating in life then when
you are within a group of individuals who are speaking a foreign language and
you struggle to understand the conversation. Trust me I should know. As a Welsh
women trying to communicate with my husbands German family! This is exactly the
same situation when you are in the middle of a group of scuba divers. They
speak the language of “Scuba” which is a mystery to those who have not tried
that particular recreational activity, and maybe a mystery to some scuba divers
themselves! Use my alphabet jargon guide to help you establish some basic scuba
language skills so you are not left completely in the dark and you can impress
your companions with your knowledge of their chosen sport!


A = Ali 80

This is the typical reference to a common
size and material of scuba diving cylinder. The material of the tank is made
from aluminium and the size of the tank is 80 cuft. This is typically the type
of scuba tank that you will find in most scuba diving resort destinations.



The buoyancy control device, or buoyancy
compensator (BC). It’s basically a jacket that you wear which you can put air
inside, so helping you to float more easily or you can take air out which would
then make you sink. The BCD is the platform of your scuba diving gear that
provides stability both on the surface and underwater. It holds the rest of the
scuba equipment in place, lets you carry a cylinder on your back with minimal
effort, keeps you afloat on the surface and allows you to achieve neutral
buoyancy at any depth. It is the key to enjoying your diving, diving
comfortably and diving safely.


C = Cargo shorts

Basically a pair of shorts that you can wear
in the water to allow for more storage of your bits and pieces. The shorts can be worn above a dry suit or a wet suit to create additional pocket
space, or can be worn alone for use in warm water or for other aquatic
activities. Ideal for warm water diving conditions where the additional storage
of slates, spools or torches is required while wearing a wet suit.



Also know as a Scooter. I am not referring to
the two-wheeled motor vehicle or the child's toy. No, a
scooter is actually an underwater driver propulsion vehicle (DPV). Think of
James Bond in Thunderball and you get what I mean. A DPV usually consists of a pressure resistant
watertight casing containing a battery-powered electric
, which drives a propeller. They are used to aid divers who wish to cover larger distances or
where strong currents exist. The use of the scooter can minimalize exertion and
is also great for divers with physical disabilities.


E = Equalisation

The process of balancing the pressure within
your ears and other body cavities to the increasing pressure as you descend in
the water. This simple process is achieved primarily by pinching the nose and
blowing out against it. You will feel the ears “pop” just like being on an
aeroplane. The process is essential during descent to avoid any discomfort or
damage to the ears and sinuses.


F = First Stage

The first stage is the name given to the part of the breathing
device (the regulator) that is attached to the scuba cylinder to enable gas to
be transferred from the scuba tank via a hose to the diver. The first stage is
vital as it reduces the high pressure of the scuba cylinder into an intermediate
pressure that enables the diver to breathe at all depths.


G = Gas

In order to breathe underwater you need to
have a gas supply. This comes stored in a scuba cylinder typically carried on
your back, and traditionally within an Ali 80 (see letter A). The gas that you
breathe could be standard air or it could be in the form of Nitrox; (see letter
N) a gas with more oxygen added to it.


H = Harness

Compared with the typical 'jacket style' BCD, the
harness with back inflation style wing systems (see letter W) offer precise
control of buoyancy and trim as well as having a very streamlined profile with
the entire front of the diver being clear from clutter. This modular system means you buy a harness and then
add on whichever wing suits the type of diving you will be doing.


I = Ice Diving

As the name implies this type of penetration diving
is in areas where there is a frozen surface. A hole is literally cut into the
ice surface into which the divers will make their entrance and exit. Divers
would typically be tethered to a rope with a line tender feeding line out as
the diver swims away and recoiling the line in and the diver comes back to
avoid entanglements.


J = Jack Cousteau

The Godfather of the scuba diving community. Jacques-Yves Cousteau AC was a French naval officer,
explorer, conservationist, filmmaker, innovator, scientist, photographer,
author and researcher who studied the sea and all forms of life in water. The first commercially successful scuba sets were the Aqualung twin hose open-circuit units developed by Emile Gagnan and Jacques-Yves
in 1943.


K = “K” Valve

The name given to the common valve that you
see on the majority of scuba cylinders. The
names come from the item numbers that were used to identify the valve in the
early catalogs. (A "L" valve was item L; the "K" valve was
item K, etc.


L = Lazy Shot

A length of rope with a floating buoy on the
top and lead weights on the bottom that acts as a reference point for divers
when making their ascent. Divers making long ascents can physically hold this
line to aid control and exertion levels. The length of the line only needs to
be as long as the depth of the first depth where the divers will stop at. It
can be attached to the main shot line or completely independent.


M = Manometer

An instrument used to monitor scuba cylinder
gas pressure throughout the dive. More commonly know as a Submersible Pressure
Gauge (SPG). They could be in metric form where they give readings in Bar, or
in imperial form where they give readings in PSI. (see letter P)


N = Nitrox

Or also known as Enriched Air Nitrox (EAN).
This refers to any nitrogen/oxygen breathing gas mixture
with an oxygen concentration higher than the 21 percent found in normal air. 32
percent oxygen is the most common, and cylinders filled with EAN are often
clearly marked with a green and yellow nitrox tank band and have the mix
percentage written clearly. It is this higher percentage of oxygen, and the
proportionately lower percentage of nitrogen, that allows divers to lengthen their


O = Octopus

Not one of the 8 legged kind, but a slang
word for the alternative air supply that each individually diver is carrying to
assist their buddy in an out of gas or low on gas situation. Typically it would
be a brighter colour, generally yellow, to make it clear and easy for the buddy
to locate if required. It is also typically a slightly longer hose length to
enable more comfort when sharing gas with the buddy.



Pounds per square inch. PSI is a measurement
of pressure. The size of a scuba cylinder is measured by the cubic
feet of air it holds. Because air can be compressed, the same physical size
cylinder can hold different amounts (different numbers of cubic feet) of air. The construction of the cylinder determines
how much air and pressure it can contain. Most scuba cylinders today have a 3,000-lb. per square
inch (psi) fill level.


R = Rebreather

A rebreather is a form of SCUBA (Self
contained underwater breathing apparatus) where the exhaled gas from the diver
is recycled. Through the removal of the toxic expired carbon dioxide and the
addition of life sustaining oxygen a series of sensors enable the diver to
maintain a safe breathing gas for an extended period of time.


S = Split fins.

As the name implies it is a set of scuba
diving fins that each blade has a split going down the middle, in essence
splitting them into two parts. The scuba diving industries Marmite. You either
love them or you hate them! The split blades, which act like
propellers, twist independently during each stroke to a precise angle of attack
that creates lift and thrust. Typically the fin is longer than traditional
paddle blades and so not so desirable in any overhead environment.


T = Trimix

A gas mixture typically composed of three
gases (hence the word tri); Oxygen, Nitrogen and Helium. It is a Trimix gas
that is breathed by divers looking to make deeper dives where the helium acts
as a “gap filler” when oxygen and nitrogen levels need to be relatively low to
avoid physiological problems.


V = Vortex Assisted Design (VAD)

A patent by Mares of second stage regulator design to
enable easy breathing at all depths. As air comes from the second
stage hose, it passes into the second stage body and is conveyed directly to
the mouthpiece through the by-pass tube. A "vortex" is created in the
airflow as it enters the mouthpiece. In the center of this swirling air is an
area of a low-pressure. This low
pressure helps keep the second stage diaphragm down during inhalation, thus
increasing the regulator's sensitivity and minimizing respiratory effort.
Regulators with the VAD system, offer improved performance and allow for very
natural and comfortable breathing.


W = Wing

A type of BCD (see letter B) that primarily
holds all of the air behind the diver. Larger versions of wings which have
greater volume capacities can look like a diver has “wings”.


Y = Yoke

A yoke or also known as “A Clamp” is the name
given to a design of first stage (see letter F). The Yoke sits over the top of
a tank valve as is secured by a tightening screw. Yoke style regulators are
more common in the US and the UK.


Z = Z Knife

A compact cutting tool sharper than most dive knifes and does a much
better job of cutting through monofilament, fabric, small-diameter rope, and
line. It is the preferred cutting tool for cave and warm-water divers.

Written by
Profile Cat
When 30th June 2016
Location Hurgada - Al Ismaileya, Qesm Hurghada, Red Sea Governorate, Egitto

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Stefan Michl on Jun 21st 2016
Hi Cat, very nice alphabet and for sure all divers around us would have tons of further meanings/products related to the alphabet letters. Lets see whether others will let us know their alphabet.... A first teaser for mine: M = MARES J = Just add water R = #realdiving S = SSI ;-) Stefan

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