In 2012, some members of the International Submarine Safety Forum (ISSF) decided that an equivalent code to the Naval Ship Code should be developed for Submarines and work on the Naval Submarine Code began.
The working groups took the Naval Ship Code as the baseline and developed submarine specific chapters and text maintaining commonality with the NSC wherever possible. The development continued and the Naval Submarine Code is considered to be at a similar level of maturity as the Naval Ship Code.
The Naval Submarine Code has three parts; Part 1 contains the Regulations, Part 2 is designated for Solutions but is not populated (relying instead on the user selecting appropriate standards) and Part 3 contains the Code Justification and Guidance. The Naval Submarine Code is not yet openly published and is only available to INSA members who contribute to its development. Those nations may publish it under their own cover for use on their projects and in doing so, they may choose to populate Part 2 with their own solutions.