Sea: it is the amount of salt water which covers 3/4 of Earth's surface. In Greek mythology, Sea was anthropomorphic goddess after Poseidon.
Scuba Diving (Self Contained Underwater Breathing Apparatus): It is the capability of diving autonomous using diving equipment The difference between a scuba diver and a regular diver is that the scuba diver bears compressed air device, which offers him great autonomy underwater, but the regular diver is dependent from the "cord" which provides air or gas mixtures by station on surface.
Mask: Is one of the most important parts of diving gear. Regarding size, there is a small volume mask and big volume mask. Correct size on the face, good vision and good materials are primary factors should a diver consider before choosing the right mask for him.
Diving-Fins: They are flexible, lightweight fins that give comfort, flexibility and speed to the diver. There are two types of fins, the open type and the closed type. In scuba diving it is better to use the open type fins, because allow better movement of the leg, better thermal protection since they are combined with diving-boots and give comfortable walking on rough road. Fin blades can be soft or hard, depending on the material.
Snorkel: It’s a piece of equipment used on surface that allows the diver looking from surface below without taking his head out from the water to breath. There are many types of snorkels, which differ in design and material. A diver must check that the tube is not be longer than 42cm, a reflective tape is on the top of the tube so its visible from afar, a mouth-piece soft enough and a strap so it can be attached to a mask.
Diving-knife: Is important piece of diving equipment for safety reasons. Of course, the knife is not considered as weapon, but as a very important tool, which the diver can use it to cut a rope or a net underwater.
Buoyancy Control Device (BCD): It’s very important piece of equipment that allows the diver to adjust his buoyancy underwater by altering the volume. When it’s on surface, playing the role of a "lifejacket". The BCD can be filled mechanically by a low-pressure tube pressing a button or by mouth. It has also valves to remove air. There are two types of BCD. The jacket’s type and “wing’s” type. Both types offer to the diver the best security and balance when underwater or on surface.
Pressure regulator: It is a device, which reduces the absolute air pressure of the cylinder to a breathable pressure. There are two parts, A’ stage and B’ stage. Regulator gives the opportunity to use low and high pressure, which can help a diver to fill the BCD, use the backup second stage (octopus), and the console.
Weight belt: Controls also the buoyancy of the diver. It is important for a belt has quick release buckle, mechanisms of restraint and proper distribution of burden sharing. Putting it on correctly will be comfortable and avoid complications with the cylinder or the BCD.
Diving suit: The diving suit used for thermal protection, protection against injuries and abrasions that may be caused by contact with objects in the bottom. Diving suits are divided in wet type suit, semi dry suit and dry suit. The most popular is the wet type suit and the semi dry suit. The dry suit is used for more specialized kind of diving like underwater constructions or in extreme low temperature conditions. All types of suit can be found in different designs, colours and sizes.
Diving Air Tank: It is a cylinder, which the diver can safely carry high-pressurised air. All cylinders have the shape and size according to the international standards for diving. Most often, we use cylinders of 10, 12, 15 and 18 lit. Filled by atmospheric air or a mixture of gases, in pressure 200 – 300 bars. The material used is steel or aluminum. Because the high pressure in cylinders is constant, there are construction specifications set by international organizations. The most famous is the DOT (Department of Transportation) in the U.S., the DIN (Deutsche Industry Norman) in Germany and EURS (European Standards). Each organization requires certain information to be written on the cylinders such as construction material (for steel 3AA and 3AL for aluminium cylinders), date of manufacture, capacity, operating pressure, number of each cylinder and the hydrostatic test date. The cylinders have valves, which connect the pressure regulator.
Consoles: Consoles contain all the necessary instruments for a dive, including diving depth (depth meter), cylinder pressure (manometer), underwater direction (Compass) and temperature of water (Thermometer). All these instruments have a mechanical function and gives a lot of information during the dive, so the diver can stay in the limit of his dive plan.
The last 20 years technological progress helps to calculate all the parameters of a dive through the Dive-Computers. Although dive computers are becoming more reliable and the analogue instruments become better and better, they cannot replace the real physiology of a diver and for this reason a diver should always be careful and not exceed the limits of its capabilities.