This submersible paper model is the HU06 Shinkai, designed by oniya, this is the fifth submersible papercraft from the author, other 4 submersible paper models here:
Shinkai 2000 Submersible Free Paper Model Download
Nautile Submersible Free Paper Model Download
Mir-2 Deepwater Vehicle (Submersible) Free Paper Model Download
DSV Shinkai 6500 Submersible Free Papercraft Download
Julius Perdana from paper-replika has also designed a submersible paper model, named "Deepsea Challenger (DCV 1) Deep Submergence Vehicle", it is a great paper craft too.
You can download this paper model from here: HU06 Shinkai Submersible Free Paper Model Download