The Koreans are so proud that they have made at least two reconstructions of these ships relatively unknown to Westerners. Undoubtedly the centerpiece of the marine arsenal of the Chosons, they come from a line of military ships quite surprising originally imagined to contain massive raids of Japanese pirates. The turtle-boat - so called because of its domed roof made of iron scales - was indeed an invention that Leonardo da Vinci would certainly not have denied:
It is simply the first battleship. Its propulsion was assured both by short oars, and thin battened veils, constituted as on the junks of the time, of canvas issued from rice mat, maintained by bamboo yards, pivoting on the axis of the mast And very easy to stir.. from the inside. For in the vast comparative bestiary, the hedgehog would have been equally appropriate to deal with this ship. The roof was, in fact, devoid of any access (which was made by the back of the gallery), but on the other hand furnished with sharp points, generally hidden by boots of straw, so as to discourage collisions. What's more, this roof was high enough for the junks of the time. To this passive protection was added a formidable battery of cannon mounted on rolling carriages (6 to 12 per side), and the arms of the men on board.
The dragon's head, at the beginning lower, was in fact the exit of a barrel pulling from the front. Later, this head served either as a flamethrower in the manner of the Byzantine siphons, or as a thick smoke to conceal the maneuver. The Geobukson (or Kobukson) is large and high, relatively slow but stable, and Eminently formidable. Few of them were produced, but only at the instigation of Yi-Sun-Sin, which took over the "naval base" of the province of Cholla.
Korea was in open war with Japan, whose fleet had heavy and powerful ships. The turtle ship is mentioned from the time of King Taejong (1400-1418), but remained in the prototype stage. It was not until the Ijmin war in 1592 that the Admiral took up the idea of this ship and allowed it to pass to the stage of mass-production. Three will see the light of day in 1592 and two others in 1595 which will have decisive weight in the battle alongside Panokson, largely the majority. Their action can be compared with that of the handful of Venetian Galleads at the battle of Lepanto.