The Turtle Ship, which is also known as Kobukson or Geobukseon (거북선), is a galley that was invented in the 15th century. While the Korean Admiral Yi Sun-sin is often credited for inventing it, he only revived and revised it for use in the 1592 to 1598 war against the conquest of the larger, more powerful Japanese armada.

Considered one of the first ironclad warships in the world, it had armour covering the top of the ship that protected rowers and seamen, and looked like a turtle, hence where its name comes from. The armour had iron spiked to prevent the enemy from jumping aboard to seize the ship. The mouth of the dragon head-shaped mast shot fumes to deteriorate its visibility.

It was most famously utilized in several sea battles, led by Admiral Yi Sun-sin, especially at the battles of Noryang and Myungrang, where the invading Japanese navy suffered critical defeats that would later lead to its withdrawal.

Europeans had tried to make ironclad ships previously, but the iron weakened the European wood; this didn't happen to the Southeast Asian hardwood.