1st, July 2011 was a glorious day.

It marked the 90th anniversary of the birth of the Communist Party of China.

China's manned submersible Jiaolong set sail on this day to an area in northeastern Pacific Ocean for the "5,000-meter sea trial." This was a significant decision taken by the sea trial leading group to embark on a special expedition on the 90th birthday of the CPC and the decision was made after a comprehensive examination of the marine meteorological conditions and thoughtful preparations. At nine o'clock in the morning, the test mothership, the Xiangyanghong 09, stood ready, full of festive atmosphere. Flags were hoisted on the superstructure of the deck. On its left hung a banner reading: "Bearing in Mind the Expectations of the Motherland and the Chinese People and the Resolutely Completed Mission of the 5,000-metre Manned Deep-sea Dive of the Jiaolong Submersible". All of the staff, in their uniform sea trial costumes, lined up on the port side of the deck.

A ceremony had been held earlier on the dockside, where the Jiangsu CPC Party Committee and Government presented gifts to sea trial teams. Huang Lixin, a member of the Provincial CPC Standing Committee and Vice Governor, handed gifts to the Chief Commander, Liu Feng, and the Secretary of the Provisional CPC Committee, Liu Xincheng. Liu Cigui, the Director of the State Oceanic Administration, who was new to the role, led a delegation to board the ship and to inspect the submersible, the submarine preparation room, the kitchen, restaurant, wet and dry laboratory, the crew cabins, the operator cabin and the on-scene headquarters. He also talked by video-conference with the staff in the COMRA general office under sound audio and video conditions.

Delighted, Liu Cigui said to the two leaders of sea trial: "You carry grave responsibilities on your shoulders. I hope you will work actively with great enthusiasm and join hands to overcome difficulties and to fulfil the mission. We depend on you!"

"Director, please rest assured that we will work hard and strive resolutely to complete the mission", Liu Feng and Liu Xincheng replied in unison, full of confidence, ambition and pride.

It was an unprecedentedly grand occasion.

After the successful 3,000-metre sea trial of the Jiaolong manned submersible, a press conference was jointly held by the MOST and the SOA, releasing relevant information about the sea trial and arousing strong sensations at home and abroad. People.cn, joining hands with Sina.com, the State Oceanic Administration network, the China Ocean News, Oceanol.com, the China Ocean News mobile newspaper and other media organizations launched an event to draw on public opinion to select the top ten "2010 Maritime Figures". The honour would be awarded to those who had made an extraordinary contribution to China's maritime development, to the protection of marine resources and the environment, to publicizing maritime history and culture and to advocating for the awareness of maritime undertakings in 2010. Their deeds would have a great social impact. The votes from Internet users, as well as the review conducted by a committee of experts, placed China's manned submersible deep-sea trial team on the list.

Fame led to extensive worldwide exposure. With its name now known to many and with missions ahead, the Jiaolong submersible shouldered even heavier responsibility.

On 30th December 2010, the group leading the manned submersible sea trials held a meeting in Beijing to review the 3,000-metre sea trial and to make plans for sea trials of 5,000-7,000 metres. Prior to this meeting, and taking account of the situation, the MOST and the SOA believed that the Jiaolong submersible was well- conditioned to reach the depth of 7,000 metres and, thus, had decided to speed up the sea trial process to expeditiously complete the trial and to engage in deep-sea scientific research. The two departments submitted a report to the State Council entitled "Organizing the 5,000-7,000-metre Manned Submarine Sea Trial".

The attendees set a detailed plan for organizing the 5,000-7,000-metre sea trial. They emphasized that lessons should be drawn from the successful experience of the 3,000-metre sea trial, that communication should be strengthened at all levels, that all departments and parties should be encouraged to exercise their unique advantages and that resources should be pooled nationwide to secure the implementation of the sea trial. All participating departments were required to improve their organizational structures at all levels, to clarify their responsibilities and the division of labour, to further refine their plans and to make contingency plans for all links, including shipping, equipment, foreign relations and assistance and rescue in order to ensure the smooth progress of the mission.

Drawing on the merits of the two previous successful sea trials, the meeting continued to adopt a five-level organizational structure that included the leading group, the on-scene headquarters, the mother ship, the submersible and the persons-in-charge of the guardships, the chiefs of work divisions and the operating staff at each post. Wang Fei, Deputy Director of the SOA, continued to serve as the head of the leading group for the sea trial. The original sea trial team basically remained the same as this was deemed best in respect of ease of coordination and for the common goal of engaging in the process from the beginning to the end to witness the sweeping victory of China's 7,000-metre manned submersible!

However, there was no area in the South China Sea suitable for the 5,000-metre sea trial as COMRA had signed a contract with the International Seabed Authority for the exploration of polymetallic sulphides within an area of 75,000 km2 in the north-eastern Pacific. The contract stipulated that the Chinese government was committed to annually investing in scientific research in this area. Based on a comprehensive consideration, the leading group for the sea trial decided that the 5,000-metre sea trial of the Jiaolong manned submersible would be carried out in the contracted exploration area in the north-eastern Pacific in order to conduct studies on polymetallic sulphides and biodiversity while applying the study results. This dual track approach would help the team further discover and solve problems through the application.

This sea area is about 5,000 nautical miles from Shanghai, China, with an average depth of around 5,200 metres.

The Xiangyanghong 09 had been in service for 34 years and was suffering from declining power, lower speeds and frequent failures. On 19th January 2011, Liu Xincheng, Deputy Director of the SOA North China Sea Branch and the Secretary of the Provisional CPC Committee, organized the relevant departments of the branch, the First Detachment of the China Marine Surveillance, personnel from the Oceanographic Technology Center and the relevant experts in order to conduct an on-scene inspection of the Xiang 9 and to engage in in-depth discussions. A consensus was reached that large- scale repairs needed to be carried out to restore the ship's technical performance and to correct various parameters to their normal values to ensure operational safety and reliability.

Following the meeting, the North China Sea Branch submitted a written report to the COMRA general office on the opinions of the experts, as well as the budget. Ten days later, Liu Feng, the Deputy Director of the COMRA general office and also the on-scene Chief Commander called to say that the general office had received and studied the report from the North China Sea Branch on the repairs to the Xiang 9. The office agreed with the opinions stated in the report, approved the necessary repairs and hoped that the branch could strengthen the organization to deliver the expected results and to ensure the smooth progress of the sea trials.

The Xiangyanghong 09 sailed into the shipyard on 29th March 2011 and a programme entailing a total 297 repairs was completed within two months. Forty-nine of the repair programmes focused on the extensive repair of the main engines, including the replacement of two main engine piston rings, nine cylinder sleeves, three piston rods, three pairs of main bearing shells, two governors, 18 air distributors, six cylinder oilers, a major overhaul of six superchargers and the inspection and measurement of 36 pairs of crosshead and bearing shells. The subsequent sailing test proved that the ship could reach speeds of 15.8 knots and could fully achieve the purposes for which the extensive repair of the main engines had been undertaken.

The on-board computer network system was upgraded from a hundred-trillion level to a gigabit level. The video surveillance in the on-scene headquarters was transformed. The deck survey equipment was maintained and calibrated. The Branch carefully selected 48 officers to participate in the 5,000-metre sea trial, 35 of whom had participated in the first two sea trials and were familiar with the work. Meanwhile, the team completed the voyage planning and approval, the procurement, supplement, sea chart updating, book replacement and the formulation and revision of nine kinds of contingency plans.

In addition, refuelling in preparation for the voyage was a seemingly ordinary but, actually, a daunting task. The tanker volume of the Xiang 9 was 900 tons and, conventionally, the refuelling volume should not exceed 90% of the tank's capacity. However, taking into account the necessary margins, it was calculated that the voyage to the north-eastern Pacific would consume 880 tons of fuel. The national maritime authorities stipulate that the captain or the chief of the engine department should be held accountable in the case of an oil spill, meaning that the mission would suffer either insufficient fuel or risk an oil spill. The chief engineer, Liu Jun, and the relevant personnel thoroughly studied the situation and were extremely careful at every step of the measuring and filling of the oil. They eventually refuelled 887 tons of oil.

When Secretary Liu Xincheng checked the voyage preparations, experienced Liu Jun told him: "We've never filled so much fuel in a single task. We were so nervous that we sweated."

Providing meals for the 96 sea trial members during the 50- day non-stop voyage remained a challenge. The leadership of the First Detachment of the China Marine Surveillance was concerned about the food supply and had a mentally exhausting discussion with the leadership of the Xiang 9 and the cooking staff about the procurement of staples, vegetables and fruit. From the North China Sea Branch, only 48 personnel participated in the sea trial, but more than 500 people worked directly to secure the supply for the Xiang 9, which carried the Jiaolong submersible to carry out the tasks of the sea trial.

By that time, Dou Yonglin had been promoted to the position of Deputy Chief of the First Detachment of China's Marine Surveillance and Chen Cunben had taken over as captain of the Xiang 9. Chen is a Qingdao native. He was trained in ship navigation and after graduation from the Naval Aviation University, he was assigned to work in the North China Sea Branch where he remained for decades. Good at learning and reviewing, he became a captain at an early age. He had sailed to Antarctica three times and was assigned to serve as a captain for oceangoing ships in five shipping companies. He had crossed the four oceans several times and travelled to more than 200 ports in 39 countries. His experience equipped him with superb driving skills. When the mothership of the Jiaolong submersible was looking for a new captain, he was a natural choice.

On the afternoon of 30th June 2011, Liu Cigui, Director and Secretary of the CPC Committee of the SOA, made a special trip to Jiangyin to see off the Jiaolong submersible, which would set out the next day. Liu Cigui had just taken over from Sun Zhihui, who had retired from the role of Director of the SOA the previous February. Born in September 1955 in Quanzhou, Fujian Province, Liu had been the Mayor of Xiamen, Fujian Province and had completed a postgraduate education. In his childhood, he lived with his father who worked at Weimin Forest Farm in Shaowu County, which was not far from the sea. As a result, he was familiar with the sea. Seeking a political career, Liu Cigui served as the Executive Vice Mayor of Putian City, the Party Secretary and Director of the Fujian Provincial Bureau of Ocean and Fisheries, the Deputy Party Secretary and the Mayor of Xiamen. Working in the coastal cities of the southeast, he used his spare time to pursue advanced studies in oceanography at Xiamen University. It is fair to say that he is an authentic "expert of the ocean".

As early as in 2007, when Liu Cigui took office as the Mayor of Xiamen City, he attached great importance to maritime industry by vigorously developing the marine economy and marine S&T and he worked on coastal disaster prevention and mitigation. Early in the morning of 20th September 2010, on receiving the news that Typhoon Fanapi was about to land in Zhangpu County, Liu rushed overnight to the Xiamen Flood Control and Drought Relief Headquarters. His command secured victory in the fight against the typhoon. Further, he emphasized the need to develop marine culture and leveraged on the SOA to build the "Xiamen International Ocean Week" into a brand with extensive influence. In view of his background, it is fair to say that China recognized his worth and, thus, placed him in the position of the Head of the SOA, a role that he was very capable of filling.

In order to collect materials for this book, in the spring of 2014, I went to the SOA to conduct interviews. There I received strong support from the relevant leadership. Wang Fei, the Deputy Director of the SOA and Chairman of the Executive Council of the COMRA received me with hospitality and gave me a comprehensive introduction to developments since it was the founded, especially with regard to the ins and outs of the 7,000-metre manned submersible. He recommended that I interview Director Jin Jiancai and Deputy Director Liu Feng of the COMRA, Deputy Director Liu Xincheng of the North China Sea Branch, Chief Engineer, Xu Qinan, of the CSIC and others who had made a significant contribution to the development of the Jiaolong submersible.

Later, Director Liu Cigui, who had just returned from abroad, took time out of his tight schedule to meet with me in his office. He is a man of medium size, friendly and smart with shining eyes. He spoke Mandarin with a southern accent while looking thoughtful and calm. Proceeding from the perspective of the country, the Chinese nation and history, he elaborated on the importance of developing a manned deep-sea submersible.

He particularly recalled that when he was new to SOA, he knew little about the project but during his conversation with Wang Fei and Jin Jiancai, he was deeply impressed by some of the statistics they mentioned: that the world's oceans cover an area of 360 million square kilometres, around 250 million square kilometres of which are high seas; that there are extremely rich mineral resources in the seabed and if those deposits were to be laid on the surface of the Earth it is estimated that they could be as thick as 200 metres; and that, until now, only the United States, Russia, France and Japan have been able to carry out manned deep-sea dives--China's Jiaolong submersible, which reached 3,700 metres in recent sea trials, brought China into the league as the fifth country.

As sensible as Liu Cigui is, he immediately made the decision: "Well! We must speed up the sea trial of the Jiaolong submersible and pursue its early application!"

From then on, he conducted comprehensive investigations and quickly adapted to his new role. For the sea trial of the Jiaolong submersible, in particular, Liu made persistent efforts on the basis of what his predecessor had achieved, requiring relevant departments to give the go-ahead and publicizing the marine development in newspapers, radio and television to raise public awareness. During a work deployment meeting, he invited the CCTV to stage a live broadcast of the 5,000-metre sea trial of the Jiaolong submersible.

Some colleagues were concerned: "What if we encounter problems during the sea trial? How could we face the national or even the global audience? It is better to be cautious and prudent."

"Don't worry!" Liu replied in a decisive voice and with great confidence. "We have full confidence in the scientific team. As long as we try our best, all difficulties can be overcome. Even in the case of failure, we cannot cover up the situation, it would be better to deal with it in a transparent and open way!"

It was true that television reporters had travelled with the mothership during every sea trial to capture and collect information but only the recorded video of the successful 3,000-metre sea trial was broadcast in the press conference held later. In 2011, a publicity plan was formulated as early as the preparatory stage for the sea trials, inviting CCTV reporters to travel with the team and the Xinhua News Agency, People's Daily, Science and Technology Daily and China Ocean News to cover the latest developments. Wang Kaibo, a female CCTV hostess, was specially trained in diving in case she might be able to dive with the team to report. The support and attention on all fronts left the sea trial team feeling encouraged and empowered.

Director Liu also supported my writing about the Jiaolong submersible. On hearing that I intended to travel with the mothership, Xiangyanghong 09, for a scientific ocean expedition and to collect first-hand information on the submersible, he was very happy: "Good idea. Are we heading for the north-western Pacific Ocean in our first section of voyage this year?" He turned to Shi Qingfeng, the Director of Administration of SOA who accompanied me to the interview.

"Yes. We will carry out experimental application-oriented scientific research this year in the polymetallic sulphides exploitation identified in the contract between the COMRA and the International Seabed Authority. The first leg will begin at the end of June with a planned duration of 40 days." Director Shi, who is passionate and smart, nodded.

 "You may join in the first leg since the voyage is not too long but you will still have to seek approval from the leading group of the sea trial team. If approved, you will become the first writer to be deeply integrated into the work of the Jiaolong submersible. That's true. To write good work, we must go deep into life and know about life. I hope you will not only write about the expeditions of the Jiaolong submersible but that you will also elaborate on China's marine strategies and culture by telling the story of the Jiaolong submersible to raise public awareness. This will be a quite informative book!"

 "Thank you! I will definitely work hard towards this goal and live up to the expectation of the Jiaolong submersible team and all those engaging in China's marine undertakings. In writing this book I will contribute my bit to the effort of building China into a maritime power." My heart was filled with deep veneration when I looked at him, a director who always has maritime affairs on his mind.

I subsequently went through all the levels of the application and approval procedures and was finally approved to travel with the Jiaolong submersible for the scientific expedition in the summer of 2014. This unforgettable voyage laid a solid foundation for the writing of this book.

Let us now turn the clock back to 2011. Before the 5,000-metres sea trial set sail, a seminar was held in the Hongshengyuan Hotel in Jiangyin City, where SOA Director, Liu Cigui, SOA Deputy Director and head of the group leading the sea trial, Wang Fei, Director of Administration of SOA, Li Haiqing and Director Jin Jiancai of the COMRA general office met with representatives of the sea trial team: nine diving personnel including Yu Hang, Ye Cong, Fu Wentao, Tang Jialing, Cui Weicheng, Yang Bo, Zhang Dongsheng, Liu Kaizhou and Wang Kaibo (CCTV reporter), the Chief Commander, Liu Feng, and Secretary Liu Xincheng.

This was the first time that Director Liu Cigui had met with representatives of the sea trial team as well as the first time that the Head of the SOA had personally seen the Jiaolong submersible leave. He shook hands with each member of the team and sat at the table to learn about their studies and training. He then said in earnest: "The nine of you are the representatives of the 96 sea trial team members and you are heroes. On behalf of the CPC Committee of the SOA, the SOA and its subordinates, as well as the leading group for the sea trial, I'd like to extend my sincere gratitude to all the sea trial team members! The Jiaolong submersible has completed a 1,000-metre and a further 3,000-metre sea trial. The dive to 5,000 metres beneath the sea surface is of ever greater significance. The changes in the depth and the sea area will bring about new challenges. Although you have made contingency plans, you still need to be mentally prepared for all kinds of possible difficulties arising from this complicated situation."

On 1st July 2010- the 90th anniversary of the founding of the Chinese Communist Party, the 5,000-metre sea trial team of China's Jiaolong submersible set off aboard the mothership, the Xiangyanghong 09.

At 9:40, led by the bright red CPC flag, highlighted with the golden sickle and hammer, and with a prolonged blow of the whistle, the ship slowly left Jiangyin and headed towards the northeast Pacific, embarking on a new journey for the 5,000-metre sea trial of the manned Jiaolong submersible and the scientific exploration of the ocean.

(selected from Jiaolong's Sea Explorations by Xu Chen, published by China Intercontinental Press in 2019)