In line with the traditional structure of Korean ships, the panokseon had a U-shaped hull and a flat keel. This feature was due to the nature of the Korean coastal waters, which have a large tidal range and flat, expansive tidal plains. A flat keel enables a ship to sit comfortably on the tideland when the tide is out, after coming ashore or inside a wharf at high water. It also ensured greater mobility and a shallow draft and in particular allowed a ship to make sharp changes of direction at short notice. This panokseon was one of the main reasons why Admiral Yi was able to employ the Crane Wing formation at the Battle of Hansan Island with great success.