Na Dae-yong

According to the address to the throne written by Na Dae-yong, he worked in army for 6 years to defend the northern lands and 7 years to defend the south lands, and worked under Yi Sun-sin as Battleship Managing Military Officer (감조전선출납군병군관; 監造戰船出納軍兵軍官).

One of the Panokseon's chief features was a higher upper deck, which hindered enemy boarding attempts and enabled the Korean crews to fire their arrows further.

Na Dae-yong designed the turtle ship as a combination of the best features of the Gwaseon, the Byeolmaengseon, and the Panokseon.

Its hull is likely based on the Panokseon, but the top deck was completely covered like with the Byeolmaengseon, and the spikes on its roof came from the Gwaseon.

After that, Gwanghae-gun Ilgi shows that the Saheon-bu (사헌부; 司憲府; Office of the Inspector General) and the Sagan-won (사간원; 司諫院; Office of the censor general) had repeatedly asked for Na Dae-Yong's removal from his position as governor of Gonyang (1608) and magistrate of Namhae district (1610).

These offices are organizations responsible for licensing officials, impeachment and legal inquiries and had a duty of criticizing and giving some feedback about the king's orders.

In these documents Na Dae-yong is depicted as a greedy, silly alcoholic who exploited local people with his power.

The model of the Turtle Ship and documents alluding to Na Dae-yong are in the Joseon Dynasty section in the Room of War History.

[5] The Sochungsa (소충사; 召忠祠) memorial was erected to extol Nadaeyong's patriotism and endeavors to reinforce the combat capabilities of the navy.