KOREAN TURTLE SHIP 1430   

The turtle ship had it's deck made firm with boards from two inches to a foot thick, and it was roofed with iron plates on boards, and numberless spikes on them which prevented the enemy from boarding.
Although it's crew could look at the enemy from the ship, the enemy could not see into it from outside.
The bow is shaped after the head of a dragon and the stern the tail of a turtle.
A gun-port is installed at each end of the dragon head, and six more on each side of the ship. The name turtle ship is derived from the shape.
It had eight oars on each side and two sails used for maneuvering.
The masts were designed to stand up or lay down as necessary.
It had a total of 24 cabins: two were used as storage for iron products and metal works, and three for guns, bows, arrows, spears, swords and other weapons. The rest of the rooms were quarters for the crew.
In the upper part of the ship were two cabins; one for the captain and the other for the officers.