The first turtle ships were built in the early 15th century CE, though soon fell into disuse.
When Toyotomi Hideyoshi made attempts to invade Korea in the late 16th century CE,
the design was revived by admiral Yi Sun-Sin.
The most common Korean warship of the time was the "panokseon", a sturdy multi-decked galley with a small keel to handle shallow waters.
The turtle ship basically was a panokseon topped with a spiked roof.
They were 30 - 40 meters long, 8 - 9 meters wide, with 2 masts, 2 decks and 8 - 10 pairs of oars.
On the prow was mounted a dragon head that could emit poisonous sulfur smoke; at the waterline a ram was mounted.
The ship had room for 10 - 11 small cannons on each side, 1 - 2 at the front and 1 - 2 at the back.
There was room for 70 - 80 rowers and 50 - 60 sailors and marines.
The closed deck protected the crew from small missile fire.
Spikes were added to hamper boarders.
Some sources claim that the hull was ironclad, but this is very unlikely.
Turtle ships were maneuverable but slow.
The captains sometimes relied on their cannons and small firearms and sometimes used their ram too,
or both by ramming first and following up with a broadside volley.
The cannons could be loaded with cannonballs or large javelins.
The turtle ships were used with great success in several naval battles in 1592 CE, but failed to make an appearance six years later during the second Japanese invasion.
They were used on and off into the 19th century CE.
War Matrix - Turtle ship
Age of Discovery 1480 CE - 1620 CE, Weapons and technology