1. Never hold your breath
Never hold your breath is one of the basic diving instructions to practice this sport safely, also the most important rule of scuba.
If you hold your breath, the air pressure in your lungs is certain, but as you float up and down, the water pressure around you will have a substantial change, when your lungs will rise and shrink like a balloon, in serious cases, direct lung bleeding. And your scuba tank to provide you with air and you exhale the air to ensure that the pressure in your lungs and the outside is roughly equal. You must continue to do normal breathing.
By the way, if the tank is out of air and needs to float in an emergency, you also need to open your mouth slightly and make a slight sound (hoarse ah sound like:ah... ah...), so as to ensure that the trachea is open and the air pressure in the lungs can be regulated without causing bleeding in the lungs.
Avoiding pulmonary barotrauma is easy; simply continue to breathe at all times.On the other hand, slow, deep and continuous breathing will help us reduce air consumption and precisely control buoyancy.
2.Always Ascend Slowly
In addition to not holding your breath, rising slowly from a dive is another primary rule of diving. Coming up quickly after a dive can cause "bends" or decompression sickness as the nitrogen is forced into the bloodstream. By coming up slowly from the dive and staying safely, the nitrogen in your body has a chance to dissipate and therefore will not cause harm.
3. Never Diving Alone
The old adage “when you dive alone, you die alone” exists for a reason. The majority of emergency skills rely on the presence of a buddy. For example, without the possibility of an alternate air source in an out-of-air situation, you have very few options. (So it’s also very necessary to wear a spare air source)
4.Double check all your scuba equipment.
Before diving, it is essential to check your scuba gear, or check the scuba equipment with your buddy each other, to make sure you all haven't missed anything, which is usually more effective than self-checking.
5. Keep an eye on your Gauge
You need to know when your tank is half full and quarter full so you can plan your return to the water accordingly. Always be responsible for your air consumption.Essentially, you should always factor a margin that leaves enough air for a slow ascent and a safety stop.
6. Ensure in a stable state
Diving should be fun, Never put yourself in an uncomfortable situation. If you are not physically or mentally capable of diving, or if you feel that the conditions on the day are unsafe, then you should consider whether to still dive.
7. Dive within your limits
8. Remember Your Objective
The primary objective of every dive is for everyone to come back safely. Do not let secondary objectives, like photographing a certain species or seeing a specific part of a wreck, get in the way of remembering your primary objective.
9. Get proper dive specialty training before diving
Proper training can make you more comfortable underwater, which is the key to safe diving. Don't rely on your dive instructor too much, until a life-threatening situation arises, only you can save yourself.
10.Do not dive in these situations
Do not drink alcohol before diving, and do not dive after catching a cold or taking cold medicine
Drinking alcohol can lead to dehydration of the brain due to alcohol consumption and can cause symptoms such as headache and dizziness. Also, drinking alcohol may cause vomiting that leads to choking. In serious cases, drinking alcohol can cause excessive heart pressure or water loss. Cold medicine has the side effect of making people dizzy, so do not dive after taking cold medicine.
11. Don't Fly Until at Least 24 Hours After a Dive
Due to the excess nitrogen in your system, it's important not to fly until at least 24 hours after your last dive. (Some agencies specify 18 hours, but 24 remains the norm). Flying in a pressurized environment can cause decompression sickness if time is not allowed beforehand for the nitrogen to dissipate.
In addition to the above, there are many other details that need attention in diving, not listed here
Staying safe while diving is simple. With careful preparation, common sense and skill confidence, the potential risks are effectively minimized. Following these rules and the other guidelines of your training not only keeps you safe, but also allows you to relax and have fun. And that, after all, is why you go diving in the first place.