Before diving into the deep sea, we must first receive professional training and do a physical examination to ensure that our physical condition can support us to enjoy the underwater world. Secondly, the preparation of diving equipment is also essential. In the last issue, we introduced the selection points of diving suits, masks, and breathing regulators. This issue will take you to understand diving equipment such as depth gauges and diving computers, cylinders, fins and weight systems.
1. Depth gauge and diving computer
Depth gauge and diving computer are essential equipment in the deep sea. They are like divers' "smart assistants" that accurately monitor diving depth and time in real time, helping divers to strictly follow safe diving plans and avoid falling into dangerous situations due to exceeding safe depths or staying too long. So how to choose high-quality depth gauges and diving computers?
Depth gauge
>>> Accuracy: Professional divers should choose depth gauges with an accuracy of 0.1 meters or higher. For example, when diving in caves, a small depth error may lead to danger.
>>>Maximum depth: Recreational diving is generally within 40 meters, so a depth gauge with a maximum depth of 60-100 meters is sufficient; technical divers need to choose a product with a greater maximum depth to meet deep diving needs.
>>>Display: There are pointer and digital types. The digital reading is intuitive and clear, and it is easier to read data underwater in poor light.
Diving computer
>>>Function: Basic functions include depth, time, decompression calculation, etc. Advanced functions such as gas switching reminders and wireless connection to cylinder residual pressure sensors are very important for technical divers. For example, when diving with multiple gas bottles, the gas switching reminder function can avoid the risk of running out of gas.
>>>Algorithm: Choose a decompression algorithm that suits your diving type. The Bühlmann algorithm is commonly used for recreational diving; technical diving requires a more complex and accurate algorithm to calculate the decompression time.
>>>Durability: The diving computer must be able to withstand high pressure underwater, be corrosion-resistant, and have a battery life that can meet the diving time. The casing must also be sturdy to prevent collision damage.
2. Gas cylinders
As oxygen storage containers, gas cylinders must be strictly checked for air pressure before each dive to ensure sufficient gas supply to meet the needs of the entire diving process.
When purchasing gas cylinders, we should pay attention to the following points:
>>>Material
- Aluminum alloy gas cylinders: light weight, corrosion resistance, suitable for recreational diving. For example, for people who travel frequently for diving, aluminum alloy gas cylinders are easy to carry, not easily corroded in seawater, and have a long service life.
- Steel gas cylinders: high strength, low price, but heavy, suitable for use in fixed diving locations, such as some seaside diving clubs, which do not have too many requirements for the weight of gas cylinders, and steel gas cylinders are cost-effective.
>>>Capacity
- Small capacity gas cylinders: usually 3 liters - 6 liters, suitable for shallow water areas or short-term diving for beginners, because of their small size and light weight, beginners are easier to control and operate.
- Large capacity gas cylinders: generally 12 liters - 15 liters, suitable for experienced divers to conduct longer diving activities or deeper waters.
>>>Valve
- K valve: simple structure, reliable, cheap, but no gas volume display function.
- DIN valve: can withstand higher pressure, has good sealing performance, suitable for technical diving or situations where high-pressure gas is needed.
>>>Safety
Check the manufacturing process and quality certification of the gas cylinder to ensure that it meets the relevant safety standards. At the same time, the gas cylinder needs to be inspected regularly to check whether there are wear, corrosion, deformation and other problems that affect safety.
3. Fins and weight system
The reasonable combination of fins and weight system can help divers achieve flexible and free movement and precise and stable balance control in the water. Suitable fins can reduce physical exertion through efficient paddling movements, and the weight system can be accurately adjusted according to the diver's own weight and equipment, so that it can maintain neutral buoyancy in the water and easily shuttle between colorful coral reefs and mysterious seabed landforms.
Fins
>>>Type
- Full sole fins: suitable for beginners and recreational divers, can provide better stability and power. For example, when snorkeling, it allows divers to swim on the water more easily.
- Split-toe fins: highly flexible, can simulate natural foot movements, suitable for experienced divers, especially in situations where precise control of direction is required, such as underwater photography.
>>>Material
- Rubber fins: soft and flexible, can provide greater thrust, but relatively heavy, suitable for use in calm waters.
- Carbon fiber fins: light and strong, with high power transmission efficiency, suitable for long-distance diving or diving activities with speed requirements, but the price is higher.
>>>Length
Longer fins can generate greater thrust, but the flexibility will be reduced; short fins are more flexible, but the power is slightly weaker. Generally speaking, taller people can choose longer fins.
Weight system
>>>Type
- Weight belt: simple and easy to use, inexpensive, suitable for recreational diving. But it may shift during diving.
- Integrated weight system: usually installed on the BCD (buoyancy control device), with good stability and better body balance, suitable for technical diving and diving activities that require precise control of buoyancy.
- Weight: The weight of the counterweight should be determined according to personal weight, equipment weight and buoyancy characteristics. Generally, a weight is estimated first, and then adjusted during diving practice to achieve a neutral buoyancy state. For example, when wearing a thicker diving suit, more counterweight is needed.
In addition to the above essential diving equipment, here are some small tools to help you return to land safely:
Diving knife: It can be used to cut off obstacles when encountering entanglement in water plants, hooking fishing nets or other underwater emergencies. For example, when diving in some seaweed-covered waters, if you are trapped by seaweed, the diving knife can play an important role.
Underwater lighting equipment: such as flashlights or headlights, in dark underwater environments, especially cave diving or night diving, can help divers see the surrounding environment, identify directions and discover potential dangers.
Surface signal devices: such as signal mirrors, whistles and buoys. When waiting for rescue on the surface or needing to attract the attention of others, the signal mirror can reflect sunlight to send a distress signal, the whistle can make a sound, and the buoy can make it easier for rescuers to find themselves.
Safety reel: mainly used to connect yourself to a fixed object or as a guide rope, in low-visibility waters or with currents, to prevent yourself from getting lost or being washed away by the current.
Diving is a wonderful journey to explore the underwater world, and the right equipment is the key to safety. From diving suits, fins, weight systems, etc. to diving knives, lighting equipment, signal devices, safety reels and other small equipment, they are all the guardian partners of divers. Only by considering carefully and equipping with perfect equipment can you reduce risks, enjoy the fun of diving, and leave safe and beautiful exploration footprints in the blue ocean.