The descriptions of the turtleships seem to vary pretty wildly, but assuming that the description of the metal plates with spikes lining the top of the ships is accurate, wouldn't it be possible to find the remains of some of these ships off the southern coast of Korea?
Have there been any attempts by Korean archaeologists to find any of these remains? Considering Yi Sun-sin's status in Korea, I'm surprised that all I can find online are replicas that were built.
I remember one of the few descriptions of turtle ship from the Imjin War period (by Admiral Yi's nephew) only mentions that Turtle ship has
It seems only the spikes are not made of perishable material.
However, Korea continued to use turtle ship all the way up to early modern period, probably with upgrades etc. In fact, even the US (yes, US) reportedly encountered one during the 1866 General Sherman incident.