Answer:
The Hunley Submarine was designed to dive completely below your average Submarine water level in depths. (initially)
Step-by-step explanation:
First, you should know that " '...Submarines with hull diameters ranging from 4 to 7 meters are restricted to one deck...' " source of this isn't from me.
The Hunley Submarine was made out of 40 feet of bulletproof iron it was the best and the most dangerous creation. Its purpose was to sink down many ships and one of them was the enemy ship, the Union vessel Housatonic. Although it did not change the course of the "Civil War" but it did altered naval warfare forever.
These are what I believe to be the strategy behind the development of"Hunley Submarine" though I could be wrong... Hope this helps you!