Since its establishment, Joseon devoted significant efforts to reorganizing its naval forces due to the continuous invasions by Japanese pirates(Wokou) that began in the late Goryeo period. As a result, an institutional naval system dedicated to maritime defense was established in the early Joseon period. By the time of King Sejong, the scale and organization of the navy had been systematically restructured.

Exhibit #3, "Wealth Chart of Naval Base," is a ledger and handover document recording the changes in inventory at Jeolla Naval Base in 1837. This document meticulously details the assets held by the base at the time, including the sizes of military ships, weapons and equipment on board, and other naval supplies.

On the right side of the display case, you can see items related to Admiral Yi Sun-sin. As the 'Samdo Sugun Tongjesa", encompassing Jeolla, Gyeongsang, and Chungcheong provinces, Admiral Yi Sun-sin led the Korean navy to victory in over 20 battles during the seven years of the Imjin War, starting from the Battle of Okpo and through to the Battle of Noryang. He was killed in 1598 during the Battle of Noryang, the last naval battle of the Imjin War. His death marked the end of the prolonged conflict, and he is revered to this day as a national hero who saved Korea.

Exhibit #8, "Drafts of War Reports," is a transcription by a third party of the reports Admiral Yi Sun-sin sent to the court during the Imjin War. It contains 68 entries, beginning on April 25, 1592, and through to April 20, 1594. The documents mainly detail the movements of the Japanese forces, victories over the enemy, and the achievements of the military commanders and naval forces. It is a valuable resource that provides detailed information about the Joseon navy and the events of the Imjin War.

Let's also take a look at the screen displayed in the back. This is the "Folding Screen Illustrates of the Naval Training," depicting the training exercises of the Joseon navy. The "Samdo Sugun Tongjesa" was based in Tongyeong, where large-scale training exercises were held regularly in the spring and autumn. Naval forces from the three provinces of Gyeongsang, Jeolla, and Chungcheong all gathered to participate in these exercises. During the Spring training, known as 'Chunjo,' about 30,000 soldiers would mobilize in Tongyeong along with over 500 ships, including Panokseon and Geobukseon(Turtle Ships).

Upon closer examination of the painting, each warship is equipped with naval flags at the front and rear. These flags indicate the ship's position within the fleet formation and its affiliated region. For instance, the warship in the top right corner of the central panel is the "Samdo Sugun Tongjesa"(Commander of the Three Provincial Fleets)'s flagship, the "Samdo Jusa Dodok Command Ship," bears a flag labeled "Gyeongsang Jwasu," signifying its responsibility for the right flank of the naval formation. Additionally, the flags at the forefront of each unit are colored red, yellow, black, green, and white, designating the front, rear, left, right, and center positions within the naval formation. This intricate detailing in the painting provides a valuable resource for understanding the deployment and organization of the Joseon navy's fleet in the later period.

In this section, we have a model of the "Turtle Ship," a famed warship of the Joseon navy. The Turtle Ship is a modified version of the traditional Panokseon, featuring an armored deck shaped like a turtle shell, equipped with spikes to thwart enemy boarders. It also features a dragon head at the bow, which was used to fire cannon to intimidate the enemy. Records from the Imjin War highlight that a small number of these ships inflicted significant damage on the Japanese forces. Since then, the Turtle ship has been underscored as the premier assault vessels of the Joseon navy. This model is a 1:6 scale reproduction of a Turtle Ship from the Imjin War, restored in 2022 by the Korean Naval Academy Museum.