Abstract
The internal deck structure of turtle ship has been investigated with the following approach manner. Firstly the 5 species of turtle ship are identified by examining the characteristics of 5 turtle ships revealed by the librarian or paintings. Secondly the centers of gravity and buoyancy for each type are calculated to evaluate the turtle ship's buoyancy stability. Thirdly the optimal deck structures for 5 turtle ships are additionally assessed from the viewpoint of the interoperability of soldier's missions to get more meaningful conclusion. From the results obtained by the well refined analyses above, one can identify that Changjeguyseon and Lee Chung Mu Gong descendent family's turtle ship possess one layer deck, and the tongjeyoung and jwasuyoung turtle ship consist of 1 and half story deck, and the one disclosed by Yoon has 2 story structure.