St. John Island is the Guanyu (Official Island) of Zhenghe in Singapore
For years, scholars have been unable to identify the ancient place names on the route of Admiral Zhenghe’s voyage passing through the waters of ancient Singapore, known as Temasek then. This author from his knowledge of modern maritime science has been able to pin-point these ancient names using the magnetic needle route (sailing directions), voyage and water depth from ancient books and nautical charts.
The Discovery of Guanyu (Island)
The Mao Kun map (茅坤图) in Wubei Zhi (武备志) (Records of Armaments and Military Provisions) written by Mao Yuanyi (茅元仪) in 1621, is the sole publication on Admiral Zhenghe’s nautical charts. Picture 1 shows a section of these charts on his return voyage from the Official Factory (官厂) which is a transhipment base, in Malacca, through the Singapore Strait via Baijiao (白礁, Petra Blanca). The author has added modern names (in red) onto the map for easy study.
Although Zhenghe’s chart marked Guanyu (an Official Island) 官屿for an island in the Singapore Strait, no one has determined which island it was in our country and its significance.
Some of the important names on Zhenghe’s chart are explained below:
Picture 1: Navigation chart of Zhenghe from Malacca to Petra Blanca East of Singapore
Guan Chang (官厂) (Official Factory): Gong Zhen (巩珍), an official of the Ming court accompanied Admiral Zhenghe on his seventh voyage, wrote in the Xiyang Fanguo Zhi 《西洋番国志》 in 1434, that the junks of the expedition used Malajia kingdom (present Malacca) as an outpost, erected wooden fence, set up four gates and drum towers, and built inner fortification like city wall, complete with warehouse in there. This Official Factory functioned as a transhipment station, replenishing base for the junks during the voyages from and to China and the western regions.
Jili Men (吉利门): This refers to a strait named as Auspicious Gateway situated at the southern end of the Malacca Strait, presently Pulau Karimum.
Changyao Yu (长腰屿) (Long Island）: This refers to Pulau Satumu is the southernmost Island of our waters, where the Raffles Lighthouse is situated. Changyao Yu could also be the collective name for the main island of Singapore in the Ming Dynasty. During the 17th century, the Portuguese named it the Long Island (Pulau Panjang).
Temasek Gateway (淡马锡门): This is a passageway or strait situated at the southern end of Pulau Satumu in the main Singapore Strait. It is also called Temasek Strait.
Longya Men(龙牙门) (Dragon Teeth Gateway): Wang Dayuan 汪大渊of the Yuan Dynasty (1349) wrote in the Daoyi Zhilue 《岛夷志略》that there was a gateway or strait formed by two rocky out-growths on the waters of the Temasek kingdom. The feature appeared like two dragon teeth.
This Longya Men refers to the western end of the early Keppel Harbour. At the entrance of the gateway, with a depth of 19 metres, there were two rocky out-growths on the sea separated about 100 meters apart. Both rocks had been blown up by the British in 1848. The western rock was located at the outer water of Labrador Park, whereas the eastern rock was located at Tanjong Berlayar just outside the southern point of Labrador Park. The Malays called it Batu Berlayar, the sailing rock.
After passing through the Longya Men in the middle of the two rocky out-growths, there were tall trees on both sides of the entrance of the Keppel Harbour. Documents from the Yuan Dynasty recorded that when a ship passed by there its mast would rub against the tree branches, meanwhile pirates would take the opportunity to jump from the branches onto the ship to loot.
Longyamen (Strait) (龙牙门(海峡)): The name is similar to the previous one, but this duplicate name does not refer to the two rocky outgrowths of the Keppel Harbour entrance. Many ancient books have recorded a name Longyamen (Strait) on the route that Admiral Zhenghe's fleet passed through ancient Singapore. This Longyamen (Strait) should refer to the main strait of Singapore on the south side of St. John Island (Guanyu官屿). The reason could be that it was not far from the Longya Men rocky outgrowths at the Keppel Harbour entrance as well as the present Sentosa Island. So, it is called Longyamen (Strait) (See map in Picture 2).
Guanyu(官屿) (Official Island): This name refers to present day St. John Island. Picture 2 shows that this island is 7.3 nautical miles eastward from the south of the Raffles Lighthouse.
The name Guanyu 官屿also appeared in Indonesia and Mauritius on other navigation charts of Zhenghe.
These islands might have similar functions to the 官厂Official Factory in Malacca, but their scale and status could be lower rank than that of the Official Factory.
Baijiao (白礁) (White Reef): This refers to (a group of rocks) at Pedra Blanca, belonging to Singapore, at the eastern end of the Singapore strait where the present Horsburgh Lighthouse stands.
Singapore Strait sailing directions as described in ancient books
Let’s look at Zhenghe’s route in the Singapore Strait as recorded in ancient books:
1. Shunfeng Xiangsong 《顺风相送》, a Ming dynasty navigation manual written in 1593《 Xin Fum Siam Sum》 kept in the Oxford University, Introduction by Thomas Hyde: 《Liber docens navigationem partium maris prope Chinam》 :
A. Siam (Thailand) to Moliujia (Malacca) 暹罗往磨六甲
B. Go west to No. 2 on the right side of the mountain 右边西去山二号
C. Guangdong to Moliujia (Malacca) magnetic needle course广东往磨六甲针路,
D Malajia (Malacca) returns to Guangdong magnetic needle course满喇咖回广东针路
While taking the Karimum Hill吉里闷山course one must follow magnetic needle Dan Chen 单辰 (120 degrees) (name on the compass) and magnetic needle course Yi Chen 乙辰 (112.5 degrees), at the 2nd geng 二更 (4.8th hours), after steaming pass Changyao Yu (Long Island)长腰屿, it is not advisable to go any further south, as the course may lead to Liang San Jiao (Pelampung reef or Red island) 凉伞礁 (红屿) and Sha Tang Qian (Pulau Nipa shallow) 沙塘浅, where there are full of hidden reefs and shallow sand banks.
Out of the Longyamen (Strait), follow the magnetic needle course Dan Mao (090 degrees) 单卯to head toward Guanyu, one must then avoid the southern Niu Shijiao (Buffalo rock) 牛屎礁 . Follow the magnetic needle course Jia Mao Zhen (82.5 degrees) 甲卯针, on the fifth geng (12th hour) 五更onward steaming, one must take the northern side of Baijiao (Petra Blanca) 白礁 in order to safely navigate towards the South China Sea to return to Guangdong.
2. Dognxi Yangkao《东西洋考》 (Research of East and West Ocean) written in 1617 by Zhang Xie 张燮 in the Ming dynasty.
3. Routes on 郑和航海图Zheng He's sailing charts.
Using two sets of magnetic needle course 1D plus 3, the exact distance and sailing direction in the Singapore Strait can be drawn to show the track of Zheng He's fleet, as shown in Picture 2.
Except for 1B, all five routes indicate that the sailing duration from Baijiao (Petra Blanca) 白礁 to Longyamen (strait) 龙牙门(海峡) requires five gengs五更. One geng 更is 2.4 hours, and the fifth geng is 12 hours.
1A, 1C and 2, the sailing duration of the three routes from Longyamen (strait) to Karimum Island 吉利门is three gengs, that is 7.2 hours.
The sailing duration for the whole section of the Singapore Strait is therefore five gengs plus three gengs, that is eight gengs, which is equivalent to 19.2 hours.
The actual distance is 58.8 nautical miles, when this distance is divided by 19.2 hours, the average sailing speed is 3.06 knots (close to the average speed of 3.59 knots of Zhenghe's 15 international routes), and it can be calculated by using the geng number as follows:
a. From Baijiao 白礁to Longyamen (strait) 龙牙门 (海峡), namely St. John Island, it takes five gengs, 36.7 nautical miles.
b. Longyamen (strait) 龙牙门(海峡) is at St. John Island, and it takes three gengs (7.2hours) to reach Karimum Island, 22.1 nautical miles.
The two paragraphs a and b are consistent with the modern current chart measurements, indicating that the ancient magnetic needle routes are correct.
Shunfeng Xiangsong 《 顺风相送》 (Xin Fum Siam Sum)1D, from Malacca on the routes back to Guangdong, it mentioned the distance from Karimum hill 吉里闷山to Changyao Yu长腰屿 (Long Island Raffles Lighthouse) is two gengs, from Changyao Yu 长腰屿( Long Island) to use the Dan Mao单卯 (090 degree) magnetic needle course to reach Guanyu 官屿, but it did not specify the voyage time. Also mentioned Guanyu 官屿took the fifth gen to take 白礁Baijiao( Petra Blanca).
From 1A, 1C and 2 three routes, the entire strait voyage is eight gengs (19.2 hours). Therefore, it can be calculated that the distance from Changyao Yu 长腰屿 (Long Island) to Guanyu官屿is eight gengs minus seven gengs (two gengs + five gengs), that is there remains one geng (2.4 hours x 3.06 knots (nautical miles/hour)), which is 7.3 nautical miles.
This important figure 7.3 nautical miles is consistent with the modern figure of 7.3 nautical miles from Changyao Yu 长腰屿 (Pulau Satumu, Raffles Lighthouse) to St. John Island. This confirms that the Guanyu 官屿 (Official Island) is St. John Island.
Picture 2: Malacca to Guangdong: from Pulau Satumu(Raffles Lighthouse) to Guanyu( St. John Is.)
Importance of Guan Yu in Singapore
The hydrographic map of Singapore drew by the Portuguese astronomer and mathematician Manuel Godinho de Eredia in 1604 in Picture 3 showed there were two southern islands having the same name namely Pulo Siquijan, one of them is St. John Island.
The day before Sir Stamford Raffles arrived in Singapore in 1819, he first landed on St. John Island to meet with the Temenggong from Sultan of Johor. After that, signal station and touting ships were set up on St. John Island. This shows that St John Island was valued and developed by the rulers hundreds of years ago, and where indigenous people and Chinese immigrants lived together. Because the island is on the edge of the main strait of Singapore, the deep-water anchorage is a safe haven for junks. As St. John Island is close to Longyamen (Keppel harbour) and the estuary of the Singapore River, it is convenient for trade.
The area of St. John Island is sufficiently large, with a flat terrain it is therefore suitable for building large defence, warehouse and accommodation. During the Yongle reign of the Ming Dynasty, the control of Temasek might have been returned to the Malacca kingdom. Such a relationship made St. John Island a suitable Guanyu (官屿Official Island) as an overseas trade base for the Ming Court. This is a special relationship between ancient Singapore and the Ming Yongle Dynasty 600 years ago. This is a new historical discovery.
Picture 3: Pulo Siquijan on the map of Eredia in 1604 is the island of St. John, Guanyu (Official Island)
Ceramic shards found
The author found 256 pieces of ceramic fragments in St. John Island dating from the late Ming Dynasty and Qing Dynasty (Picture 4). These artifacts prove that there were Chinese inhabitants on the Island providing direct evidence that St. John Island is a Guanyu (官屿Official Island) during Admiral Zhenghe’s voyages. I hope that scholars can do in-depth research and archaeological excavations in St. John Island to ascertain Admiral Zhenghe's activities in ancient Singapore, and might fill a blank page in the history after the collapsed of the Temasek kingdom.
Picture 4 ceramic pieces found in St. John Island
By Captain Lim Keow Wah 28 01 2021
Many years with ExxonMobil as Malacca Strait VLCC Advisor, Port Captain and retired as Chartering Advisor.
President of the Singapore Penjing and Stone Appreciation Society
Committee of International (Singapore) Zhenghe Society
Deputy Director of Professional Zisha Penjing Pot Committee(China)
Auctioneer and Antique Collector