in boarding one ship, they could hop aboard other enemy ships in the vicinity, in a wildfire fashion. Japanese ships at the time were built with wooden planks and steel nails, which rusted in seawater after some time in service. The ships were built in a curved pentagonal shape with light wood for maximum speeds for their boarding tactics, but it undermined their capability to quickly change direction. Also, they were somewhat susceptible to capsizing in choppy seas and seastorms. The hulls of Japanese ships were not strong enough to support the weight and recoil of cannons. Rarely did Japanese ships have cannons, and those that did usually hung them from overhead beams with ropes and cloth. Instead, the Japanese relied heavily on their muskets and blades. The Korean Navy attacked a Japanese transportation fleet effectively and caused extensive damage. Won Gyun and Yi Sun-sin at the Battle of Okpo has destroyed the Japanese convoy, and their failure enabled Korean resistance in Jeolla province, in the south-east of Korea, to continue. Wakisaka Yasuharu was ordered to dispatch a 1,200 man navy during the Keicho Invasion and annihilated the invading Korean navy led by Won Kyun during a counterattack in July 1597 (Battle of Chilcheollyang). Korean Admiral Yi Eokgi and Won Gyun of Korea were killed in this combat. Hansan Island was occupied by Japan, consolidating the Japanese hold on the west coast of Korea. To prevent Japan from invading China by way of the Korean peninsula west coast, China sent naval forces. In August 1597, the Japanese Navy was ordered to occupy the Jeolla. After the Joseon Navy gave a damage Japan Navy in the Battle of Myeongnyang, withdrew North of the Korean peninsula. Jeolla was finally occupied by the Japanese Navy, and the Gang Hang became the captive. Remnants of the Korean navy led by Yi Sun-sin joined the Ming Chinese fleet under Chen Lin's forces and continued to attack Japanese supply lines. Towards the end of the war, as the remaining Japanese tried to withdraw from Korea, they were beset by Korean and Chinese forces. To rescue his comrades, Shimazu Yoshihiro attacked the allied fleet. At the Battle of Noryang, Shimazu defeated Chinese general Chen Lin. And the Japanese army succeeded in escape from the Korean Peninsula「征韓録(Sei-kan-roku)」 巻六(Vol6) "外立花・寺沢・宗・高橋氏の軍兵、火花を散して相戦ひける間に五家の面々は、順天の城を逃出、南海の外海を廻りて引退く。". Yi Sun-sin was killed in this action. Japan's failure to gain control of the sea, and their resulting difficulty