Diving Sambo

　　There are countless styles and colors of diving equipment. You can choose equipment with different characteristics according to the form and purpose of diving, your own preferences and physical characteristics.

　　Snorkel - Breathe Easy

　　You may be thinking, since scuba diving has a tank and a regulator, why is a snorkel one of the standard equipment? Because first of all, when you are resting on the surface or swimming, and your face is looking down in the water or looking for something, you can breathe through the snorkel to reduce the consumption of air in the tank. Second, when there are wind and waves on the water surface, you can use the height of the nozzle of the snorkel to usually be higher than the height of the waves to prevent water from flooding into your mouth. Third, if you are out of the water far away from the boat or shore and there is not much air left in the tank, a snorkel allows you to swim back to the boat or shore more easily, allowing your face to rest naturally in the water. When snorkeling, a snorkel is a necessary equipment. You can stay in the water for a whole day without raising your head. Give it a try.

　　The general snorkel design is an open end and a curved tube with a mouthpiece at the other end. The upper part of the breathing tube (tube body) is usually a semi-rigid plastic tube, and the mouthpiece of the lower part is mostly made of silicone. A suitable breathing tube should have an appropriate curvature (suitable for your face shape), an inner diameter of about 2 cm, and a length of 30 to 35 cm. In addition to being comfortable, a well-fitting snorkel should also make breathing easier. When trying it out, you can place the mouthpiece between your lips and teeth, and place the tube in front of your left ear. The mouthpiece should be suitable and comfortable, without scratching your mouth or causing jaw fatigue, and it should be straight when held in your mouth.

　　Mask—a window to the underwater world

　　Try to open in water Eye , all you can see is a blurry scene. This is because water is denser than air, and light will be refracted when it reaches the water. The focal length of the eyes is adjusted according to the light in the air. Therefore, the mask retains a cavity in front of your eyes, allowing you to have a clear line of sight. The biggest difference between a mask and swimming goggles is that the former covers not only the eyes but also the nose. This is because the pressure in the nasal cavity needs to be balanced to prevent squeezing during diving, so swimming goggles cannot be used for diving.

　　A general mask consists of a reinforced safety glass lens, a rubber or silicone rim that fits the face shape, and an adjustable headband that can be fixed in position. Reinforced safety glass lenses prevent shattering into highly dangerous, elongated shards of glass. The material of the group edge, silicone, is stronger than rubber. This is because silicone is 3-4 times more durable than rubber and is not easy to use. skin allergies , softer and more comfortable. Some masks are equipped with a drain valve, which is a one-way valve used to drain accumulated water inside the mask. The two most important points when choosing a mask are fit and comfort. The same is true for other equipment. An ill-fitting mask may leak and cause allergies, taking away a lot of the fun of diving.

　　To test whether the mask fits properly, just place the mask gently on your face (no need to wear a headband) and then inhale through your nose. A suitable mask will stick to your face until you exhale. Another thing to note is to make sure you can easily hold your nose outside the mask. There are many styles of masks, including single lens, two lenses and multiple lenses. Usually only two lens styles are equipped with lenses that can correct vision.

　　Before using the mask for the first time, gently wipe both sides of the lens with a soft cloth moistened with toothpaste to remove the protective oil film. The mask needs to be thoroughly washed with clean water after each use, and placed in a dry and ventilated place away from direct sunlight. If you use the mask in sea water, it is best to soak it in warm water for a few minutes to prevent the formation of corrosive salt scale. If you can't clean it immediately after use, it's best to put the mask in water, as the dried salt is difficult to completely remove.

　　Fins—provide powerful forward momentum

　　The large area of ​​the flippers can provide you with strong power, so that you don't have to rely on paddling your hands to generate power, freeing your hands to do other work. Fins are mainly divided into two types: heelless and set-foot. Slip-on fins are generally used for warm waters or snorkeling. Heelless fins are to be used with diving boots. Large, hard fins are fast to use, but prone to fatigue and cramps; small, soft fins lack the power to push.

　　Fins come in different materials, designs, and features. The design of the flippers includes: keels to increase the hardness and balance of the flippers; drainage holes to reduce resistance to the flippers to increase efficiency; and diversion channels to allow water to slide smoothly through the flippers to increase speed. The choice of fins should be based on your body shape, physical strength and diving environment. The most important thing is comfort and fit.