SCUBA DIVING : Swimming underwater or taking part in another activity while using a scuba set. By carrying a source of breathing gas (usually compressed air).
Modern scuba diving consists of one or more gas tanks strapped to the divers back, connected to an air hose and an invention called the demand regulator. The demand regulator controls the flow of air, so that the air pressure within the diver's lungs equals the pressure of the water.
1.- WHAT’S SCUBA DIVING?
Early Diving Equipment Ancient swimmers used cut hollow reeds to breathe air, the first rudimentary snorkel used to enhance our abilities underwater. Around 1300, Persian divers were making rudimentary eye goggles from the thinly sliced and polished shells of marine turtles. By the 16th century, wooden barrels were used as primitive diving bells. More Than One Breath In 1771, British engineer, John Smeaton invented the air pump. A hose was connected between the air pump and the diving barrel, allowing air to be pumped to the diver. In 1876, Englishmen Henry Fleuss invented a closed circuit, oxygen rebreather. Fleuss then decided to use his invention for a thirty-foot deep dive underwater. He died from the pure oxygen (oxygen is toxic to humans under pressure). Rigid Diving Suits In 1873, Denayrouze built a new piece of equipment a rigid diving suit with a safer air supply, however it weighed about 200 pounds. 2.- DIVING HISTORY
Houdini Suit - 1921 Famous magician and escape artist, Harry Houdini was also an inventor. Houdini's invention for a diver's suit permitted divers, in case of danger, to quickly release themselves of the suit and to safely escape and reach the surface of the water. Jacques Cousteau & Emile Gagnan Emile Gagnan and Jacques Cousteau invented the modern demand regulator and an improved autonomous diving suit. In 1942, redesigned a car regulator and invented a demand regulator that would automatically fresh air when a diver breathed.
The Cies consist of three islands, Monteagudo (Sharp Mount or North Island), Faro (Lighthouse Island or Middle Island) and San Martiño (Saint Martin or South Island).
The Faro Island is linked to the North Island by an accumulation of sand (1.200 m long) known as Rodas beach, in the Eastern side of the island.
During high tide the sea flows between the islands in the Western side, the beach sand blocks water and this is the reason why a lagoon is created between the sandy area and the rocks called “Lagoa dos Nenos”.
The highest peak is the “Alto das Cíes” (197 m) in Monteagudo Island.
The islands were formed by the end of the Tertiary, when some parts of the coast sank, creating the rías. All the three islands are the peaks of the coastal mountains now partialy under the sea and they are formed mainly of granitic rock.
Atlantic squalls pass over the islands, unloading as they collide with the coast.
Due to the high natural value of this area and to the deterioration it was suffering by human activity, it was declared Nature Reserve in 1980.
The Spanish Congress of Deputies signed a definitive agreement in June 2002 creating the National Land-Marine Park of the Atlantic Islands of Galicia, formed by four archipelagos with several Islands namelly Cíes, Ons, Sálvora and Cortegada.
The marine part of the Park is measured as a 100 meter wide strip from the shore in low tide. Since 1992 underwater fishing is forbidden in the islands.
Since 1988 the islands have a status of ZEPA and they are included in the Natura 200 network which develops European Union Directives in relation to habitats and birds. It contains one of the main colonies of yellowfoot seagull.
Some traditional activities are allowed as long as they are compatible with the environment and the preservation of natural resources.
The scrubland is formed mainly of autochtthonous species like “toxo, xesta, esparraguera, torvisco or jara”.
The woodland has suffered big alterations, since most autochthonous species are now reduced to symbolic representation. The reforestation of nearly one fourth of the surface was made with pine trees and eucalyptus. On the other hand, the strong winds with a high content in salt act as barrier in the development of the trees. Some endemic Galician coast especies grow in the dunes, beaches and cliffs under very extreme climatic conditions.
There are a lot of white and yellow daisies, cardoons and ”herba de namorar”. In Cíes live small lizards, rats and some rabbits. The more frecuently seen birds are seagulls and marine ravens. There are a great variety of marine fauna : octopus, congers, crabs...but remember that it is forbidden the submarine fishing .
The marine environment of the Park is a mosaic of different habitats that sustain an extraordinary diversity of species of flora and fauna. There are important communities like the forests of brown seaweed, or the ones associated to maërl bottoms.
We found habitats defined as of communitarian interest or high priority within the Directive Habitats of the European Union, like reefs, lagoons, or sand banks covered permanently by little deep marine water.
The marine environment is one of the greatest value of the National Park, and it’s characterized by its water clarity and its characteristically cold temperatures, with a slight warming influence brought by the warm Gulf current, and with a vertical homogeneity in the winter (13-16°C) and a stratification in summer (12-18°C) by the thermal gradient produced by the warming of the upper layers.
Due to the existence of flow towards the top of the surface, generated by dominant winds and estuarine currents, a dispersal of nutrients in deeper waters produces water rich in trophic resources which sustain rich systems of life forms ( Upwelling figure).
The coast of the Islands shows a noticeable difference between the Western face, exhibited to the open sea and the Eastern one faced Ría of Vigo. Steep cliffs in the exhibited face that are continued with vertical walls, in front of sandy grounds between rocky in the protected part.
The Western side of the Islands presents a quite homogeneous habitat. The strong surge provides high amounts of oxygen and nutrients, but just a few organisms can resist the force of the waves (seaweed, barnacles, mussels, sponges, etc).
In the Eastern part sand bottoms are combined with bottoms of maërl (pieces of shell and calcareous red seaweed). There are a lot of animals that live buried in the sand or on the rest of shells like the knives, clams, crabs, turbots, rays.
MARINE HABITAT (Depth) Depth in meters DEPTH IN THE RIA OF VIGO