The Art of Karate is the Ultimate Architecture!
To understand why Karate will never be a submarine you must understand what a submarine is. A submarine is a vessel designed to travel through a specific liquid medium. Because of this all submarines eventually come to be of similar design.
This is just the physics of the universe. The submarine is designed the way it is because that is the best shape for traveling at speed through water. Any other shape would cause the submarine to travel inefficiently.
If the sub travels too slow, it can be shot by enemy subs, and it cannot turn quickly enough to defend itself. This is all related to basic combat functions.
The art of Karate is taught by kata, and these forms are designed to travel through a different substance. Karate kata are designed to travel through air, and with an eye to the effects of gravity.
Furthermore the forms are designed around the construction of the body, and the body can react to air and gravity in many different ways.
The point here that the limit of the environment is changed by the training of the body that is traveling through it, and a study of the karate forms enable the body to change and adapt to virtually any situation, andin virtually every manner the person can imagine, or is necessary.
A submarine can never change, and if you built a submarine in a different shape, the submarine would not work, at least not as well. But Karate Masters, with there endless kata are able to assume a variety of shapes.
The more kata a person studies, the more shapes he can assume, the more movements he can do. It may have taken great intelligence to make a submarine, but a submarine will never be a Karate Master.