Turtle Ships

One of Yi's greatest accomplishments was resurrecting and improving the turtle ship (거북선; 龜船). With his creative mind and the support of his subordinates, Yi was able to devise the geobukseon, or Turtle Ship. Contrary to popular belief, the turtle ship was not actually invented by Admiral Yi; rather, he improved upon an older design that had been suggested during the reign of King Taejong.

The turtle ships designed by Yi held eleven cannons on each side of the ship, with two each at the stern and the bow. The ship's figurehead was in the shape of a dragon. The figurehead itself held up to four cannons, and emitted a smokescreen that, in combination with its fierce appearance, was meant to be used as psychological warfare. The sides of the turtle ship were dotted with smaller holes from which arrows, guns, and mortars could be fired. The roof was covered with planks and spikes. The purpose of the spikes was to prevent the ship from being boarded by the enemy. The larger Japanese ships' sides were higher than the turtle ships' and thus, the spikes prevented boarders from jumping down onto the roof without risking impalement. There were two masts that held two large sails. The turtle ship was also steered and powered by twenty oars, each of which were pulled by two men during fair conditions and five in foul seas or combat.

There is an ongoing debate as to whether the turtle ship had two decks or three; historians still have no definitive answer. Whichever is the case, it is clear that the turtle ship employed multiple decks to separate the rowers from the combat compartment. This enabled the turtle ship to be very mobile since wind and manpower could be used simultaneously. Most support the argument of two decks since that was what was drawn out in the first and second designs of the turtle ships. Some historians maintain that, since Yi was a unique individual and often pursued innovative ideas (contrary to the established wisdom of his peers), it is possible that he had the turtle ship built with three decks. It is known that his flagship, a panokseon, had three decks during his campaigns, so there is support for the belief that the turtle ship had three decks.

Turtle ships are the most famous part of Admiral Yi's fleet; however, he never deployed more than five in any one battle. The Joseon Dynasty used cannons as its primary offensive naval weapon. Historically, they had often used guns and cannons against Japanese pirates as early as the 1390s. The Joseon navy did not implement the ship-boarding strategy that the Japanese navy did, so it was imperative that their warships "stand off" from Japanese vessels. Admiral Yi made it a strategic priority to avoid hand-to-hand combat, in which the Japanese navy specialized. The turtle ship was developed to support his tactic against Japanese fleets.

Turtle ships were first used in the Battle of Sacheon (1592) and were used in nearly every battle until the devastating Battle of Chilchonryang, when a Japanese double-agent plot nearly succeeded, resulting in every turtle ship and all but 13 panokseon being sunk. The turtle ships did not re-appear in battle until the Battle of Noryang.

Turtle ships were mostly used to spearhead attacks. They were best used in tight areas and around islands rather than the open sea.

• Outline of Yi Sun-Shin (1545-1598)
  

  HISTORIC PEOPLE

  Yi Sun-Shin (1545-1598)

  Yi Sun-Shin was a Korean naval commander, famed for his victories against the Japanese navy during the Imjin war in the Joseon Dynasty, and is well-respected for his exemplary conduct on and off the battlefield not only by Koreans, but by Japanese admirals as well. Military historians have placed General Yi Sun-Shin on par with Admiral Horatio Nelson as arguably the greatest naval commander in history for his undefeated record against seemingly insurmountable odds despite no background in naval training.

  Early Life: Yi was born in Geoncheon-dong Street (건천동; 乾川洞), Hanseong (then capital, present-day Inhyeon-dong, Jung-gu District, Seoul) but spent his adolescence and early adulthood period before passing the military examination in Asan where his mother's relatives lived and where now a shrine to him stands.

  Japanese invasions of Korea (1592–1598): Yi is remembered for his numerous victories fighting the Japanese during the Japanese invasions of Korea (1592–1598). Among his twenty-three victories, the Battle of Myeongnyang and the Battle of Hansan Island are the most famous battles.

  Turtle Ships: One of Yi's greatest accomplishments was resurrecting and improving the turtle ship (거북선; 龜船). With his creative mind and the support of his subordinates, Yi was able to devise the geobukseon, or Turtle Ship.

  Japanese double-agent plot: A Japanese double agent named Yoshira was sent to the Joseon general Kim Gyeong-seo, and convinced the general that he would spy on the Japanese. Yoshira played this role until Kim began believing anything he would say.

  Joseon defeat at Chilchonryang and reinstatement of Admiral Yi: With Yi stripped of influence and negotiations breaking down in 1596, Hideyoshi again ordered an attack on Joseon. The second Japanese invasion landed in the first month of 1597 with a force of 140,000 men transported on 1000 ships.

  Battle of Myeongnyang: After careful study of potential battlefields, in October 1597 Admiral Yi lured the Japanese fleet into the Myeongnyang Strait, by sending a fast warship near the Japanese naval base and luring the Japanese fleet out of anchorage.

  Final battle and Admiral Yi's death: The battle began at two o'clock in the early morning of December 16, 1598. Like Admiral Yi's previous battles, the Japanese were unable to respond effectively to the Korean's tactics.

  Reactions by Joseon government: Admiral Yi repeatedly defeated the Japanese invasion force in battle, while preserving the lives of his soldiers and respecting their families. Yi was supported by the people of Joseon not only for his victories, but his kindness and gratitude towards those affected by the hardships of war.

  Legacy: Today, Admiral Yi is considered one of Korea's greatest heroes of all time. Koreans look upon Yi as a man of courage, perseverance, strength, self-sacrifice, intellect, and loyalty to his country.

RESOURCES
This article uses material from the Wikipedia article "Yi Sun-Shin", which is released under the Creative Commons Attribution-Share-Alike License 3.0.