Submarine underwater speed is said to be fastest with Goryeo's A-class vessel, reaching up to 42 knots. (1 knot = 1.852 kilometers/hour)
Gu Yu was not aware of this data, he just felt that the Law Ark was particularly fast, traveling downstream from Bai Town, entering the Dan Jiang at Grass River Mouth, and arriving at Dongyun City in seemingly no time.
It was not only fast, but also moved with great ease, it could elongate or shorten, enlarge or diminish, and could pass through any waterway.
The Law Ark had a space refined by the Small Universe Technique, fortified with the Five Elements Technique, providing it with certain defensive and offensive capabilities. If used in the military, it could be sent directly under the feet of the Torch Goddess, and foreign enemies would not notice it.
