Seiuchin kata was developed by Chojin Miyagi, the founder of Goju-ryu and one of Tatsuo Shimabuku's teachers.
The second formal kata learned by students, it introduces a new stance to their repertoire—seiuchin stance or soto hachiji dachi. This is a deeply-rooted stance with a lowered center of gravity and the feet turned outward at a 45° angle...providing great stability. One interpretation given to this kata is that is was designed for fighting on the moving deck of a boat.
This kata is performed in two manners. The first is at full speed, demonstrating the power of the reinforced blocks and striking techniques used against larger and stronger opponents. The second is slower version that highlights the advanced breathing techniques introduced with this kata.