Welcome to Scuba Women!
Scuba Women is a site that truly understands the needs of women divers (sorry guys). For and by women, Scubawomen aims to encourage more female participation to the wonderful world of recreational scuba diving. The site provides general information, interesting facts, dive destinations and scuba news features. It also offers advice specific to women’s issues: links to dive centres with childcare services; women buddy directories across the globe; connections to international websites like Greenpeace, National Geographic Society and WWF and links to popular dive publications.”
Why a special site for women divers?
I am regularly asked why I created this site for women divers. Why a special site when women want to be treated the same as men?
I didn’t create this site because I think that women and men should dive separately. It is simply because, when I started diving, I couldn’t find certain information specific for women anywhere else, or only after searching for a long time.
Yes, women do want to be treated the same way as men, but there are some issues that are different for women than men, because men and women are biologically different. Think of medical issues (e.g. diving and pregnancy) and scuba gear that is not always comfortable for women (e.g. some women have a lot of difficulty finding a BCD that fits comfortably).
And, believe it or not, in some cases women still aren’t treated the same way as men, so that’s another important issue. I’ve heard terrible experiences from other women divers, which has led them to join women-only dive clubs. This is not because they wanted to separate themselves, but because they were simply not accepted by the men. Most women do not want to separate themselves from men, but sometimes they just have to because of the behaviour of some men (luckily not all of them!!) who simply don’t want to treat women the same as men.
Another reason for creating a special web page is to show that scuba diving isn’t just for men and that there are a lot of women divers. I’ve often met women who wanted to take up scuba, but didn’t because they thought it was some macho sport for men only. With this site, I hope to show these women that this is not true, that scuba diving is for everyone. For women and for men!
Table of Content
History of Diving
Greek divers are deployed to attack ships in Syracuse.
± 360 B.C.
Aristoteles writes his Problemata about divers using containers filled with air to stay under water. In the same text he describes a diving bell which was supposedly used by Alexander the Great during the siege of Tyrus (in present day Lebanon).
Plinius the Elder mentions the use of air hoses by divers.
Leonardo da Vinci designs the first SCUBA (Self-Contained Underwater Breathing Apparatus). There is no evidence that Da Vinci ever actually built this SCUBA. In the end, he seems to have concentrated on refining the diving bell.
Guglielmo de Lorena is one of the first to use a diving bell to complete a one-hour dive.
The English physicist Robert Boyle studies the physical properties of compressed air, resulting in Boyle’s Law. This law describes the influence of pressure variations on the volume and the density of gases. As pressure varies greatly under water, this law is very important for divers.
The Italian physicist Giovanni Borelli designs a rebreather, a system in which chemicals are used to convert the exhaled air into air that can be inhaled again.
Edmund Haley (better known for Haley’s comet) designs a diving bell that is considered the predecessor of the modern diving bell. In this diving bell he remains under water for 90 minutes.
John Lethbridge is one of the first successful salvage divers. Using a diving bell he salvages numerous treasures from ship wrecks off the coasts of Great Britain and South Africa.
In France, Dr. Freminet completes a dive in a leather suit with a copper helmet. This “machine hydrostatergatique” further consists of an air container that is connected to the helmet via hoses.
Benoit Rouquayrol and Auguste Denayrouze design the first working breathing apparatus with demand system, the predecessor of the Aqualung. The system is also used by captain Nemo and the crew of the Nautilus in Jules Verne’s 20,000 Leagues Under the Sea.
In New York the Brooklyn Bridge is built. Many labourers get symptoms after spending a long time in high pressure caissons that are placed in the riverbed. Their disease is called “caisson disease”. In 1880, the French physicist Paul Bert determines the cause of caisson disease.
Louis Boutan takes the first underwater pictures in which he also uses artifical light. He publishes a handbook for underwater photography, La Photographie Sous-Marine.
J.S. Haldane develops a procedure to prevent decompression illness (caisson disease) and publishes the first five dive tables.
The Williamson brothers shoot the first underwater film, 20,000 Leagues Under the Sea. It takes them 1,5 years to create this silent film. The film is shot on the Bahamas.
William Beebe and Otis Barton complete several dives in the Bathysphere. In 1930 they reach a depth of 427 meters near Bermuda, in 1932 they reach 661 meters, in 1934 925 meters.
Jacques Yves Cousteau shoots his first underwater film, Par Dix-Huit Metres De Fond. The film is shot using snorkeling equipment, without scuba gear.
In 1943 Cousteau develops the “Aqualung”, a breathing apparatus with a demand system. The Aqualung is the basis of all modern diving equipment. From 1945 onwards, the Aqualung is taken into production in France.
Jacques Yves Cousteau buys the research vessel Calypso. In 1951, he leaves on his first expedition, to the Red Sea.
Dr. Hugh Bradner develops and introduces the so-called “wet suit” made of neoprene.
Al Tillman and Bev Morgan develop the first official training program for recreational divers.
Jacques Yves Cousteau is awarded the Golden Palm at the Cannes film festival for his film Le Monde Du Silence (The Silent World).
Ralph Erickson and John Cronin found the Professional Association of Diving Instructors (PADI), an organisation that specializes in recreational dive training.
After 15 years, the growth in the dive industry comes temporarily to a halt as a result of Steven Spielberg’s film Jaws. The film causes such a fear of sharks that a lot of people stay out of the water. The sequels, Jaws 2 in 1978 and Jaws 3 in 1983, also have a negative influence on the dive industry.
Craig Barshinger, Karl Huggins and Jim Fulton introduce the first commercial dive computer. This computer makes registering depth, dive time and decompression time a lot easier.
The dive industry is positively influenced by films such as Splash and Cocoon, which display a new, more positive image of the underwater world.
The recreational dive industry continues to develop, with more and more emphasis on underwater photography and video. Dive trips become more and more popular. Equipment is developed and improved further with regards to comfort, durability and efficiency. In dive training, the emphasis is more and more on training, safety and protection of the underwater world.
The most important parts of a dive kit are:
- Dive suit
- Weight belt
The dive suit keeps you warm under water. Because water conducts warmth much faster than air does, you will get cold a lot faster under water. This is why you will almost always need a dive suit when diving. Dive suits come in different thicknesses, for different water temperatures, and they can be worn with or without gloves, boots or hood.
The BCD (Buoyancy Control Device) helps you control your buoyancy. The BCD is attached to the tank, which allows you to inflate it using the air from the tank by simply pressing a button. The more air the BCD contains, the more buoyancy the diver has. The tank is attached to the back of the BCD.
The regulator consists of a first stage, which is attached to the tank, and a second stage, which you put in your mouth. The first and second stages are connected by a hose. The regulator reduces the high pressure of the air from the tank to ambient pressure, thus allowing you to breathe in the air.
Most divers use two regulators: their own regulator and an extra regulator, called the octopus, which can be used by the diver’s buddy in case of an emergency.
The console usually contains a depth gauge, a pressure gauge and a compass.
To be able to plan a dive and dive safely, you need to know your current depth. A depth gauge indicates your current depth and the maximum depth of your current dive.
During a dive, you need to be able to check the amount of air left in your tank. A pressure gauge allows you to do this.
A compass is used to navigate under water and to enable you to find your way back to the point where you entered the water.
The tank contains air that has been compressed to a pressure of about 200 bar. This way, a tank can contain a lot of air. Tanks are available in different sizes, varying from 5 to 20 liters. Most divers use 10 or 12 liter tanks.
A 10 liter tank filled to 200 bar contains 2000 liters of air. The amount of time you can dive with this amount of air depends on a number of circumstances:
- Physically fit and more experienced divers use less air than divers who are not physically fit and novice divers.
- During a shallow dive you use less air than during a deep dive.
- During a relaxed dive without currents you use less air than during a streneous dive.
On average, a diver uses about 25 liters of air per minute. Thus, a 10 liter tank would allow you to dive for about 80 minutes.
A mask allows you to see under water. If you try to see under water without wearing a mask, you will not be able to see clearly. This is because water is much denser than air; the human eye is not designed for an environment as dense as water. A mask creates an artifical air space in front of the eyes, thus allowing you to see clearly under water.
A mask cannot eliminate all distortion under water; even while wearing a mask, all objects under water will appear 25% bigger and 25% closer than they actually are.
Fins enable you to move with less effort under water. The fins more or less enlarge the surface of your feet, thus enabling you to replace more water with one fin kick than you would if you weren’t wearing fins.
The weight belt allows you to descend. Without a weight belt, you are too buoyant and you will remain floating at the surface. The amount of weight needed depends on various circumstances:
- The heavier the diver, the more weight he will need.
- In salt water you will need more weight than in fresh water.
- The thicker the dive suit, the more weight you need.
Frequently Asked Questions
What does scuba mean?
SCUBA is the abbreviaton for Self-Contained Underwater Breathing Apparatus. This abbreviation was used for the first dive gear which allowed a diver to descend independently, i.e. without an air supply from the surface. Scuba gear was invented in 1943 by Jacques-Yves Cousteau. All modern diving equipment is based on this first prototype by Cousteau.
How deep can you dive?
The depth limit for recreational scuba diving depends on the diver’s training. Most organisations prescribe the following maximum depths: 18 meters for novice divers (Open Water Diver) and 30 meters (with an absolute maximum of 40 meters) for advanced divers (Advanced Open Water and up).
These depth limits have been determined based on the pressure changes that occur under water: the deeper you go, the higher the pressure. This increasing pressure has various influences on the human body: it will cause an increasing risk of decompression illness and will reduce the ability to react. In short: the deeper you go, the greater the risk of accidents.
What is deep-sea diving?
When talking about diving, many people use the term “deep-sea diving”. Recreational diving doesn’t have anything to do with deep-sea diving; the “deep sea” starts at about 500 meters, a depth at which a recreational diver with conventional dive equipment would never be able to survive. Deep-sea diving is always done with submarines or special suits that can withstand the enormous pressure that occurs in the deep sea.
What kind of air or gas does a dive tank contain?
A dive tank contains compressed air, not oxygen. Compressed air is exactly the same as the ambient air we normally breathe, but it is compressed to enable the diver to take as much air with him under water as possible. Ambient air consists of roughly 80% nitrogen and 20% oxygen.
You will, however, often encounter tanks filled with 100% oxygen on, for example, dive charter boats, but these are only used in emergencies for injured divers (for example, divers with decompression illness).
What is caisson disease?
Caisson disease is usually called decompression illness. Decompression illness can occur when you stay under water for too long and/or if you ascend too quickly after a dive.
During a dive, a diver breathes compressed air, which consists of 80% nitrogen and 20% oxygen. Oxygen is processed by the human body, but nitrogen isn’t, which means that all the nitrogen you inhale, you will have to exhale again at some point to get rid of it. Normally, this isn’t a problem, but when diving you encounter differences in pressure under water: the deeper you go, the higher the pressure. And the higher the pressure, the more nitrogen the human body can absorb.
So, after a diving for a while, the body has absorbed a large amount of nitrogen. During the ascent, the pressure decreases and the body needs to get rid of the surplus nitrogen. If you ascend too quickly, the nitrogen is released in the form of bubbles, and this is called decompression illness. This effect can be compared to opening a bottle of soda: as soon as you open the bottle, the pressure drops and the carbon dioxide in the soda is released all at once in the form of bubbles.
The effects of decompression illness depend on the area in the body where the bubbles form; if the bubbles reach the heart or the brain, this can be fatal. Decompression illness can be treated by having the patient breathe 100% oxygen (which will help release the nitrogen) and by bringing the patient back under pressure in a special recompression chamber.
What is nitrox?
Nitrox is commonly used as a synonym for enriched air. Enriched air is air that has had some oxygen added. Nitrox refers to any nitrogen-oxygen gas mix, including blends that have less oxygen than air has.
Recreational scuba divers usually breathe normal air, which consists primarily of two gases: nitrogen (79%) and oxygen (21%). Enriched air is air that has been “enriched” with oxygen. Therefore, enriched air always contains more than 21% of oxygen, most commonly between 22% and 40%. This higher percentage of oxygen allows you to make longer dives than when breathing normal air.
However, because of the higher percentage of oxygen, enriched air has a higher potential for oxygen toxicity than normal air. Therefore, when diving with enriched air, adherence to depth limits is extremely important. When diving with an enriched air mix with a high oxygen percentage you cannot dive as deep as with a mix with a lower oxygen percentage.
Are sharks dangerous?
In films like Steven Spielberg’s Jaws, sharks are depicted as vicious killing machines. In reality, however, only 21 of the 400 species of sharks are considered a threat to humans and only 4 of these have proven to be a serious risk. Swimmers, snorkelers and scuba divers are therefore at minimal risk. In fact, more people are killed by lightning, bee stings and farm animals than by sharks every year.
Worldwide, less than 100 shark attacks occur each year, of which only 15% are fatal.
The best way to avoid a shark attack is not to swim in waters known to be frequented by dangerous sharks.
What is a rebreather and which types are there?
A rebreather is a system in which the air you exhale is processed (carbon dioxide is filtered out and oxygen is added), so that you can inhale it again. In regular diving equipment, all exhaled air vanishes into the environment and cannot be used again.
There are two types of rebreathers: fully closed circuit (FCC) and semi-closed circuit (SCC).
A fully closed rebreather will keep the partial oxygen pressure at the same level during the whole dive, regardless of depth. This will give you a lot more bottom time. To achieve this constant pressure, the system mixes air (or trimix) with 100% oxygen. If, for example, the partial oxygen pressure is set to 1.3 bar, the mixture you inhale will be nearly 100% oxygen at 5 meters; at 40 meters, it is nearly 27% oxygen. A fully closed system will also allow you to use the gases more efficiently: you only use what you need.
Fully closed systems are to be used if you don’t want to produce any air bubbles, if you want to make deeper dives with longer bottom times, and if you want to use trimix (this is because helium is very expensive and because for a fully closed system you will only need a small tank).
When using a semi-closed rebreather, the partial oxygen pressure will vary throughout the dive and a constant flow of nitrox will be injected into the circuit. The surplus nitrox will be dumped by the system (which is why you see air bubbles emerge about every five breaths you take). Diving with a semi-closed rebreather is almost the same as diving with nitrox; you can even use the same tables. The higher the oxygen percentage in the mixture, the less forceful the flow of nitrox, and therefore the longer the gases will last. However, with a nitrox mixture with a high oxygen percentage, you cannot dive very deep.
What is freediving?
Freediving is the oldest diving technique in existence and was used for the first time thousands of years ago as a way to collect food or treasures. The freediving technique was later used in military actions; Italian and French soldiers used it during the Second World War to descend to staggering depths on one breath of air to place mines.
The first official freediving world record dates from 1969 and was set by a marine diver in the United States: Robert Croft dived to 75 metres on one breath of air. In 1976, Jacques Mayol from France was the first to exceed 100 metres.
Nowadays, there are three freediving categories:
- Constant balast, where the diver must wear a weight belt while descending and returning by fin power.
- Variable balast, where the diver can jettison the weight before ascending.
- No-limits, which allows the diver to attach an unlimited amount of ballast to an underwater “sled” fixed to a line to speed the descent.
The deepest dives are made in the latter category. The current world record was set on 18 January 2000 by Francisco “Pipin” Ferreras from Cuba: 162 metres. Together with the Italian Umberto Pelizzari, he is the best-known freediver at the moment. The women’s world record (130 metres) was set by Audrey Mestre from France on 19 May 2001. Audrey Mestre attempted a new world record to 165 metres on 12 October 2002, but unfortunately she didn’t survive this attempt.