Early Joseon court references challenge the idea that turtle ships appeared from nowhere during the Imjin War. The older vessels were probably smaller than the geobukseon associated with Yi Sun-sin, which supports a continuing design lineage without making the two types identical. This earlier history matters when assessing how quickly the ships of 1592 entered service. Because even a court often resistant to naval investment discussed the earlier type, the design tradition may predate its first surviving written references.
Notable Point · 5:41-8:16
Turtle-ship precedents long before 1592
Records from 1413-1415 support a much older Korean turtle-ship tradition, with the vessels of the 1590s appearing to be larger descendants rather than sudden inventions.