Divers in romance (part 2) starting an instructor course 潛水員的浪漫（二）上了潛水教練課

After we were certified as beginner divers, we enrolled in an advanced course. For beginner divers, they are limited to maximum depth 18 meters. When they have advanced level, the limit is 40 meters and they may have night dive. 

For diving safety, every diver must have buddy. As Camilla and I were single, the instructor paired us to be the buddies. Sometimes, we needed to hold our hands under water to prevent missing, because the visibility was very low that is quite common in Hong Kong.

I learnt later that this is a merit for training, because you will not scare easily when you dive in a good visibility environment later.

An advanced diving course is a combination of several individuals diving techniques, such as night dive, deep dive, navigation, search and recovery, using diving computer and light salvage.

As there are not too many dive sites that are convenient for deep dive training in Hong Kong, we just practiced at 18 meters, which just met the requirements of the course's standard. The deepest sea in Hong Kong's region is a valley by the Beaufort Island, whose depth is 70+ meters.

Beaufort Island

 Most of the dive sites are much less than this. It is very dark at 18 meters in Hong Kong, because they are usually muddy bottom under such depth. The main purpose of deep dive training is to test whether you may experience nitrogen narcosis, which is tested by doing calculation at the bottom. At this depth, we may experience a lower water temperature, a greater water pressure, a longer descent and ascent time and looking absorption of sun light.

Absorption of sun light under various depth

Causes of nitrogen narcosis
Underwater, all nitrogen is not expelled during exhalation; when pressure increases, the nitrogen is forced from the lungs into the blood, and from the blood into the tissues, including the brain.  Nitrogen narcosis mimics alcohol intoxication. And just as with alcohol, different divers have different degrees of susceptibility to nitrogen's effects and may experience varying intensities of narcosis from one day to the next. The exact mechanics of the syndrome are not well understood. One theory is that the nitrogen blocks neurotransmitters and receptors in the brain, resulting in a distortion of electrochemical signals.

The level of the disability varies, depending on the physical and emotional state of the diver that day, the water temperature, and the extent of disorientation that can occur with ever-changing underwater visibility. The sense of time itself can grow distorted, and the diver may feel euphoric. Sometimes, a diver may feel sad, but he may also feel paranoia. Unlike an alcohol buzz, which lasts for a while even after the person stops drinking, nitrogen narcosis is thought to leave no comparable negative residual effect, and all the divers who are unduly affected have to do is ascend to a shallower depth, and their wits will return immediately. 

After we were certified as an advanced diver, we celebrated at a Sai Kung's restaurant. Camilla asked me whether I may be her buddy, because she needed more practices to gain confidence and she has been feeling she was comfortable to dive with me as I have shown I am good in the performance of diving techniques and care of her. I replied her: "Sure, why not? It is my pleasure to have your trust."

I lived in Hong Kong Island where is quite far from Sai Kung to where I had to take more than one hour public transport. She offered she may pick me up in the morning because she also lives in Hong Kong Island. It was ever the first time that I had a chance to ride by Maserati.

After we have made several fun dives, the course director who was the owner of the dive shop, Hong Kong Institute of Scuba Training, persuaded us to have further education of diving. 

What is the progress of learning diving?

Flow chart of Scuba diving courses

In simple, the next step is master diver and then rescue diver, which is the highest level of non-leadership level. The next is dive master, instructor, instructor trainer and course director, which are leadership level.

As I wanted to have an excuse to dive with her, I have desired to take these courses. I asked her: "Do you have interest to become an instructor?" She replied: "If you took instructor course, I would join also." I thought we would have many chances to meet and dive together.