I have read your artice about the admiral yi-sun sin,
and am very impressed about its quality and details.
Yet I found a minor error about the ships he commanded.

In this following sentence,
"With only 12 turtle boats left, Yi ambushed 133 enemy ships. Seemingly overwhelming odds, but the slow Japanese boats boasted only one cannon each and no armor."

He didn't have turtle ships at that battle but
Pan Ok ships(general type of battle ships of Cho Sun at time).

Without a doubt, turtle ships played an important role in battles, yet the kind of ships that played major role was
Pan Ok ships that could fire multiple cannons at once.

For reference check the following link.(In korean but includes
some pictures of the ship)
http://keons.com.ne.kr/newbatship.html