The carnage far exceeded the slaughter in Drake's defeat of the Spanish Armada, which had taken place around the world just ten years before. In fact, the Japanese loss of fifty thousand sailors was twice the combined number who'd merely sailed in the English and Spanish fleets. The Japanese were so badly beaten that they stayed away from Korea until 1904. Admiral Yi was killed in the battle. And, in a strange way, so too was the Turtle.
There is a recent book (from which the following illustration is taken)
about the "Turtle Boats" and, of course, some controversy has erupted. Info on the book here. The author apparently disputes some long-held Korean beliefs:
... he contradicted the reputation of turtle ship as being the world's first ironclad ship.
"If the ship was ironclad, the speed of the ship must have been reduced because of the iron's weight," Nam said in the book. "It is highly possible that the ship had a wooden roof covered with a thin iron plate on which big nails were hammered."