The participation of the author in the ISBSA conference in Marseille was made possible by the Seafaring: Maritime knowledge in the South China Seas project (ANR/Ecole française d’Extrême-Orient, Paris/Academia Sinica, Taipei).

1For most of its history, Korea has had its own unique ship-building tradition, distinct from the neighbouring countries of Japan and China, a fact which has recently come to light thanks to the development of underwater and intertidal naval archaeology in South Korea. The first ancient shipwreck was excavated in 1984, followed by a second one in 1995. Since then, the pace of discovery has been rapidly increasing, to the point that so far 13 ancient wrecks have been excavated in Korean waters, and two others in the city of Penglai in Shandong province, China. The vast majority of these shipwrecks are dated to the Middle Ages (fig. 1), so we now possess a good overview of what medieval Korean shipbuilding looked like, especially for the Koryo era (918-1392), when maritime activity was at its greatest in the waters of the peninsula.

3The present paper thus aims to explain the uniqueness of the Penglai 3 shipwreck through its specific historical context, as it was built at a time when the Korean court, facing many challenges from across the sea, was experimenting with various techniques in order to improve its own navy.

1. Overview of Medieval Korean Shipwrecks and Shipbuilding

5The side strakes were attached on either side of the bottom planking, rising at a steep angle, and joined together using an elaborate system of grooved clinker joints and wooden pegs (called p’isak). The strakes on both sides were then held together using throughbeams arranged in rows, which would act as a frame. The way these strakes were connected to the bottom planks evolved over time. While earlier ships used one or two rows of L-shaped chine strakes on either side to serve as a transition, these seem to have been completely abandoned in the early 13th century. From then on, the bottom side strakes were directly attached to the bottom planking using a groove joint. Korean shipwrights would typically waterproof the hull by tightly packing rice straw rope in between the planks.

7The size of the ships varied according to their use, from about 9 m for the smaller (Wando shipwreck) to 30 to 40 m long in the case of the Naju shipwreck, although only a few bottom and side strakes have been found. The length of most of the ships ranged from 12 to 17 m (Mun 2014, p. 171-184) (fig. 2).

2. The Characteristics of the Penglai 3 Shipwreck

8As stated above, the Penglai 3 shipwreck is the most peculiar Korean shipwreck excavated to date. Dating from the late 14th to early 15th century (but no later than 1420) (Kim 2009, p. 259-260), it is rather large in comparison to most Korean wrecks (the ship’s reconstructed length is estimated to be about 22 m). As is the case of other Korean ships, it was primarily made of pinewood. Flat bottomed, its side strakes were fastened using grooved clinker joints and wooden pegs, and its overall shape and basic structure can be qualified as typically Korean. On the other hand, it used bulkheads instead of through- beams in order to strengthen the hull. Furthermore, a plank resembling a keelson was attached on top of the middle row of bottom planks, and iron nails were also used along with the wooden pegs in order to reinforce the structure of the hull. It also had two masts, as evidenced by the presence of two mast steps, another innovation never found on other Korean ships, and it used a lime-based compound as luting material, as opposed to typical rice straw rope waterproofing (fig. 3-4).

9Most of these features can be traced back to either Chinese or Japanese shipbuilding. The use of bulkheads for instance is ubiquitous in Chinese shipbuilding, as is the use of keelsons (which is not surprising as Chinese seagoing junks possessed a V-shaped hull constructed around a keel), mast steps and lime-based caulking compound. However, Chinese caulking compound mixed tung oil with the lime as a binding agent, while the compound found on the Penglai 3 ship solely used lime and was, as a result, of poorer quality (Yuan 2011, p. 52-53). The use of iron nails was also common in both Chinese and Japanese shipbuilding.

10The Penglai 3 can be compared to two other wrecks dating from the same period found in Korea. The Anjwa shipwreck, dated to the late 14th century, is one of the largest Korean ships excavated to date, with an estimated total length of 17 m. The cross section of the hull shows a flat bottom with a gentle wine- glass-like turn of the bilge, slightly more elegant than earlier shipwrecks, with similarities to the Penglai 3. Although it does not have any mast step, the two mast slots on the middle bottom plank were dug into a slightly elevated platform carved on the plank, to which it added an extra third in width, a feature that so far has only been observed on this shipwreck. Another interesting point of the Anjwa ship is that it used, in addition to the traditional rice straw rope stuffed in between the planks as waterproofing, a lime-based luting material similar to the one found on the Penglai 3 (NMM 2006, p.  32, 81, 88 and 96). In fact, historical records show that Koreans knew about using lime as a luting material at least since 1412 (CWS: 1412.5.21 [3]), but only learnt about the Chinese technique of mixing tung oil (or, when not available, fish oil or sesame oil) with the lime in 1451 (CWS: 1451.3.3 [2]).

11Another contemporaneous point of comparison for the Penglai 3 is the Mado 4 shipwreck (NRIMCH 2016). Excavated in 2015, it was a government operated tax transport ship which sank en route while sailing from the south to the capital, sometime between 1417 and 1425. It is the most recent medieval wreck to be found, dating from roughly the same period as the Penglai 3. It too has a few noteworthy features, such as the sparing use of iron nails, as well as two sets of mast slots on the middle row of bottom planks, indicative of a second mast, something which had never been witnessed on earlier wrecks found in Korean waters. As the wreck has not yet been dismantled for study, we do not know what type of caulking was used.

12In summary, even though most of the features found on the Penglai 3 shipwreck can be traced back to Chinese and Japanese shipbuilding, some of them are also present on other Korean shipwrecks of the same time period, hinting at the fact that these innovations were not restricted to the Penglai 3, nor were they necessarily particular to oceangoing ships, but were in fact the result of a broader current within Korean society. It is thus essential, in order to explain the characteristics of the Penglai 3, to look deeper into the historical background of the late Koryo and early Chosŏn era.

3. Evolution of Shipbuilding in the Late 14th and Early 15th Century

13In the second half of the 14th century, the Korean peninsula was faced with an unprecedented challenge coming from across the seas: Japanese pirate fleets, gathering sometimes up to several hundred ships, raided the Korean coast year after year, rampaging and plundering villages, temples, towns, military outposts and of course ships, and capturing the populations to be sold as slaves on Japanese markets. The Koreans soon realized that their navy was ill equipped to fend off these attacks and started building new warships from the 1370s and 1380s onwards, progressively taking back control of their waters. These efforts were carried on into the new Chosŏn dynasty (1392-1910). In this process of rebuilding its naval might, the Korean court started paying a great deal of attention to Chinese and Japanese shipbuilding techniques and comparing them to their own, especially during the first half of the 15th century. They would compare the structure of the hull, the materials used for the sails and anchors (CWS: 1446.9.9 [2]), the types of wood (CWS: 1430.5.24 [1]), etc. However, the curiosity for foreign shipbuilding techniques did not stop at mere observation. Indeed, Korean authorities invited Japanese shipwrights to Korea, and had them build ships there (CWS: 1417.5.19 [2]). These ships were not meant to replace indigenous shipbuilding, but rather were used to conduct various experiments. For example, in 1413, the king ordered the conduct of speed comparisons between Japanese and Korean ships. As it turned out, the Japanese ship outsailed its Korean counterpart by 30 to 40 paces when sailing with the current, and over 100 paces when going against (CWS: 1413.1.14 [1]). The Korean authorities thus paid a great deal of attention to the strengths and weaknesses of their own ships compared to foreign vessels and tried to bridge the gap whenever possible. They also used them for experiments in naval warfare, and the development of techniques to counter Japanese tactics, such as the creation in 1415 of “turtle ships” (kwison), warships whose upper deck was covered with a spiked roof to serve as protection against projectiles and to prevent the enemy from boarding (CWS: 1415.7.16 [2]). In other instances, Japanese ships built in Korea were also used as target practice for the newly developed cannons (CWS: 1445.9.22 [2]).

14Scholars who have studied the Penglai 3 usually assume that the iron nails were introduced to Korea from China, but one cannot rule out the influence of Japanese shipbuilding in this regard. For instance, in 1421, local authorities in Kyongsang Province asked that the 34 Japanese ships captured in Japan two years prior be dismantled and their iron nails taken out to be used for the construction of new warships (CWS: 1421.3.14 [7]). Japanese nails were indeed highly praised by the Koreans, as evidenced by several texts. It is therefore quite possible that the introduction of such nails as seen on both the Penglai 3 and the Mado 4 were, in fact, the result of experimenting with Japanese shipbuilding techniques in the early Chosŏn period.

15Evidently, however, Japanese shipbuilding was by no means the only source of inspiration for Korean shipwrights. Chinese techniques, being the most advanced in East Asia at the time, were also the focus of Korean enquiries and experiments. This trend can be traced back to the year 1415, when the king mandated two Chinese men, Liu Siyi and Li Xuan, to conduct experiments with Chinese shipbuilding, because “the military ships in each province before long get eaten by worms and have to be rebuilt after a few years. Not only is it taxing on the workforce, but [Korean] timber resources cannot keep up” (CWS: 1415.11.19 [4]). It is interesting to note that this event occurred roughly around the same time as the Penglai 3 was built. One cannot but wonder if this ship was not, in fact, the direct product of those experiments.

4. Conclusion

17In conclusion, the peculiar appearance of the Penglai 3 shipwreck cannot be separated from the specific historical context in which it was built. It was not the result of technology transfers in the late 13th century nor a typical oceangoing Korean vessel, as much as it was the product of the numerous experiments conducted by Korean authorities in the early 15th century, as evidenced by the fact that some of its unusual features have also been found on other contemporaneous ships excavated in Korean waters.

18The enthusiasm of Korean authorities for such innovation and experimentation started to wane in the second half of the 15th century. Many of the techniques newly introduced, such as double planking for the hull, iron anchors, and indeed most of the hybrid features found on the Penglai 3, seem to have been abandoned thereafter. Some of them, however, were retained by Korean shipwrights, and remained an integral part of Korean shipbuilding until the early 20th century. Indeed, although no Korean wreck later than the early 15th century has been discovered so far, we know from pictorial and textual evidence from the 18th and 19th centuries that some of the features adopted in the early Chosŏn period became the norm, such as the use of iron nails as a supplement to wooden pegs (NRIMCH 2016, p. 388), and the construction of two-masted ships, which seem to have become common for middle-sized and larger ships for most of the Chosŏn period, from fishing vessels to warships (NRIMCH 2012, p. 139-158). In this respect, it seems fair to say that the late 14th and early 15th centuries were a defining period for Korean shipbuilding.

List of Abbreviations

19CR&AISP: Cultural Relics & Archaeological Institute of Shandong Province, based in the city of Penglai, China.

20CWS: Chŏson Wangjo Sillok (Veritable Records of the Chŏson Dynasty).

21KRS: Koryŏsa (History of Koryo), compiled in 1451. NMM: National Maritime Museum, present day National

22Research Institute of Maritime Cultural Heritage (see below).
NRIMCH: National Research Institute of Maritime Cultural

23Heritage, based in the city of Mokp’o (South Korea).