Battle of Chilcheollyang The naval Battle of Chilcheollyang took place before dawn on August 27 , 1597 ( the 15th day of the 7th lunar month 1597 ) during the Imjin War in Chilcheollyang , which is a narrow strait near Geoje island . It took place during the second invasion of the Japanese . This was the only naval victory for the Japanese during the War . Prelude . A Japanese double agent was dispatched by the Japanese commanders to bring false information to Admiral Yi and move him into a trap where he could be killed . For a time , the double agent brought what appeared to be important information to the Koreans . At one point , the agent brought reports of Katō Kiyomasa planning to invade Korea to Gim Eung - seo , a commander of Gyeongsang province . The agent brought the exact place and time of where the Japanese fleet would come . The agent insisted that Admiral Yi go out and intercept the Japanese fleet and destroy it . Gim sent the message to General Gwon Yul , who sent it to Seoul in March 1597 . King Seonjo ordered Admiral Yi to attack but Admiral Yi refused , reportedly not trusting a lone letter delivered by an agent and feeling he was unable to prepare for battle in time . Admiral Yi may also have believed that there was a trap at Chilchonryang ; the hazardous area contained sharp rocks . For his refusal , King Seonjo ordered Admiral Yi to be court martial ed and stand trial in Seoul . In addition , Won Gyun accused Admiral Yi of drinking and idling . He was spared the death sentence due to his combat record and prime minister Yu Seong - ryong ' s support . The decision to remove him may have significantly affected further historical events . Chilcheollyang . Won Gyun replaced Admiral Yi as the naval commander of the entire Korean fleet . Won Gyun decided to attack a large Japanese flotilla of which he did not know the size , strength , or location . He decided to look for the enemy navy with the entire Korean fleet that Admiral Yi had carefully built and strengthened . Won Gyun left Hansando on August 27 , 1597 , and soon met a very large enemy fleet near Pusan . Won Gyun was shocked to see the Japanese navy of a size of at least 500 to 1000 ships . Even though his troops were tired , Won Gyun ordered the attack . At the moment of the attack , a commander named Bae Seol quickly ran away with 13 ships under his command knowing the results of the battle ahead . Of note , it was these 13 ships that Admiral Yi would use to defeat the Japanese at Myeongnyang Straits upon his reinstatement . ( Commander Bae Seol deserted with his single ship before that battle as well . ) The Koreans advanced quickly with barely any strategy when the Japanese returned fire with arquebus es . The Japanese destroyed at least 30 Korean ships by rowing close to the Korean ships and jumping aboard to begin melee combat . The Koreans had no chance to fire with cannons . Won Gyun retreated back to nearby Gadeok island suffering even more damage to his ships . Apparently , Gadeok island was under Japanese control and when Won Gyun landed with his troops in search of food and supplies , the Japanese commander Chikushi Hirokado of the fort and the island attacked the Koreans and killed 400 Korean marines . Won Gyun quickly retreated and left Gadeok Island . The Japanese were surprised at this terrible performance of the Korean navy and set out at once to attack the Koreans at night . It was a disaster for the Koreans and the Japanese used their traditional grapple and board attack to overwhelm the Koreans . Admiral Yi had always kept hold of the upper hand by blasting the Japanese from a distance , but Won Gyun had allowed the Japanese to attack the Koreans with swords and spears . After a surprise attack , 200 Panokseon s and other Korean ships sank to the bottom of the ocean . Won Gyun was shocked at this attack and retreated quickly again while the Koreans were struggling . Won Gyun and Yi Eok - gi , another general , struggled ashore at a nearby island with a few survivors . Again , there was another fort with a garrison of Japanese soldiers who rushed outside and killed every single Korean , including Won Gyun and Yi Eok - gi . Aftermath . The Battle of Chilcheollyang resulted in the destruction of the Korean navy and a huge loss of life . When King Seonjo and the Korean court heard of the battle on July 22 , they were left shocked and devastated . They pardoned Admiral Yi ( who had spent some time as a common foot soldier under General Gwon Yul ) , and put him back as the commander of the now small and weak Korean fleet on the same day . With only 200 men , and the 13 ships that Bae Seol had fled with , Admiral Yi then had to fight the Japanese with overwhelming odds against him . Although he had a disadvantage , Admiral Yi would emerge as a hero and victor at the Battle of Myeongnyang when he destroyed a Japanese fleet of 31 ships with only 13 ships ( minus the ship captained by the once again fleeing Bae Seol ) . The immediate consequence was a near complete collapse of the allied defenses in southern Korea , as the Japanese forces were now able to surge forward without having to worry about their logistics being destroyed by the Korean navy . Key southern defensive fortresses such as Namwon were left completely exposed . Within weeks , the Japanese forces took much of Jeolla province and surrounded the fortress of Namwon , and then took it in the ensuing Siege of Namwon . Sources . Annals of Seonjo