Scuba Diving Equipment – an overview
Scuba Diving Equipment – an overview
Scuba diving equipment is designed to overcome the limits of human physiology in the submarine world and although the number of items may seem daunting to the beginner, everything has a clear purpose. Below we look at the main items of scuba diving equipment used in recreational diving.
Mask
Divers wear a face mask for the simple fact that it allows them to see underwater. The human eye is not designed to see in water, which has a different optical density to air. By simply having an air space between eyes and water the mask allows the diver to see, although the optical density means that all objects appear larger or closer when underwater. Traditionally masks were constructed from neoprene, which tended to age relatively quickly. Today's scuba masks generally consist of a lightweight plastic frame, glass lenses and a silicone rubber skirt that seals against the face. Modern masks also allow a smaller volume of air between the water and the face, which is an advantage because it means it is easier to equalize the pressure in the mask and simpler to clear of water.
Wet suit
While a wet suit is the most common type of suit worn in recreational diving, it is not the only type. Primarily to prevent the diver from losing body heat to the water, which conducts heat from the body at a much faster rate than air, a wet suit consists of a layer of low density neoprene which acts as an insulator and traps a thin layer of water between the neoprene and the diver's skin, also helping to minimize heat loss. The secondary function of a wet suit is to protect the diver from abrasions and other injuries, including stings and venoms.
When the water is too cold for a wet suit to be used divers can wear a dry suit, which as the name implies keeps the diver dry by sealing at the neck and wrists, while in warmer water divers can wear a lycra body suit which provides no thermal protection, but prevents against scrapes and stings as well as sunburn.
Fins
In the same way that fish glide through the water by moving their fins, scuba divers are able to propel themselves through the water by kicking their fins. Usually made of neoprene for the foot and rigid plastic for the blade, there are two main types; full foot and adjustable. With the former the diver simply places the boot of the fin over the bare foot, while adjustable fins have an adjustable heel strap and are usually worn over wet suit boots.
Scuba tanks
The scuba tank – also commonly known as a cylinder or a bottle – contains the divers breathing gas at high pressure. Usually the breathing gas is air, although in some circumstances other mixtures are also used.
The standard configuration in recreational scuba diving today attaches the tank to the BCD (buoyancy control device), often known simply as a jacket. The tank is attached to the rigid backplate with an adjustable strap and the BCD is then worn like a waistcoat and fastened at the front with a cummerbund.
As well as providing harnessing the scuba tank, the BCD is designed to allow the diver to adjust buoyancy in the water by either adding or reducing the amount of air held inside. Many modern BCDs also have pockets to hold lead weights, traditionally worn on a belt around the waist.
Regulators
The first stage regulator is attached to the top of the tank and reduces the pressure from the tank to supply the second stage as well as providing the air for BCD inflation. The latter supplies the diver with air at ambient pressure and is located in the mouthpiece on most modern equipment.
Scuba diving computers
Until relatively recently divers used tables to plan their dives, designed to reduce the possibility of decompression sickness. A depth gauge a dive watch were essential items to ensure the dive was within the limits of the table.
While divers are still taught dive table theory, most recreational divers quickly move on to buying a dive computer, which effectively calculates a custom table for each dive. More sophisticated models also connect to the air supply, so that they act as timer, depth gauge and air pressure monitor all in one.
About the Author: David Leigh usually dives year round in the Costa Brava in Catalonia. You can find more information about scuba diving equipment at www.CostaBravaScubaDiving.com.
How to choose scuba diving equipment – selecting a scuba mask
When selecting a scuba mask it is essential that it fits your face well to ensure that it is both comfortable and leak free. Without a good seal against the face you may spend much of your time clearing the mask of water, while an uncomfortable mask detracts from your diving experience – both lead to enjoying your dives less but because they distract you from your environment they are also potentially unsafe.
Finding a mask that fits your face well is a simple matter and can be tested with the following three-step procedure:
1. Place the mask on your face but with the strap placed out of the way.
2. Inhale slightly through the nose so that the slight vacuum holds the mask on your face.
3. Test the fit by gently moving your head and it should remain in place if you gently try and pull it away from your face.
At the end of this test you will have determined whether a scuba mask fits your face well or not, so now it is time to examine other features.
Style
Most masks on the market today have low internal volume, which means that the mask is more comfortable to use since the diver won't experience much mask squeeze during the dive. This style of mask is now usual and features a pocket for the nose that protrudes forward of the lenses and as well as low volume the large lenses allow for a wider field of view, but models to look for include Cressi Big-Eyes, although it is not suitable for all face shapes.
Colour
This is purely a matter of personal preference and you may not have any preference at all. The traditional colour for masks, and all dive equipment in fact, was black due to the use of neoprene. These days silicone is used instead for masks, which is more flexible and less susceptible to sun damage. Silicone can be supplied transparent or in a multitude of shades due to the use of colouring agents, but many people still choose black. However, some people claim masks made with transparent silicone give better visibility due to the greater amount of light allowed to enter.
Skirt
High quality scuba masks feature a silicone skirt that thins towards the edge, allowing for a better and more comfortable fit against the skin of the face. Often you'll see a second skirt inside the upper edge of the skirt that allows a better seal. Its absence at the bottom is to allow water to drain more easily from inside the mask.
Strap
There are many occasions when you'll need to adjust your mask strap and so ensure that you find the mask easy to adjust. If you wear gloves when diving then make sure you can adjust it quickly and easily with gloves on. And while on the subject of mask straps, remember to always carry a spare – it is one of the more common equipment failures and the lack of a spare may mean you have to remain on the boat when everyone else is enjoying the submarine world.
Those are the most important factors to consider both when buying a new scuba mask or using rental equipment from a dive centre. By ensuring a good fit you ensure your own comfort and safety while a combination of the other factors will mean you get many happy years of service from your scuba mask.
About the Author: For more information on diving equipment including scuba masks see http://www.CostaBravaScubaDiving.com .