We recommend that submarine builders that share our enthusiasm about the possibility to build a affordable submarine yacht with ocean crossing capacity do not try to tackle the matter from zero.
As it takes a long time skill and know how build up to create a concrete submarine hull as suggested at (concretesubmarine.com).
It is our dream to move submarine yachting forward. We offer those hulls at a incredibly low price because we want fellow builders and outfitters to start their own projects without paying the cost of try and error involved in the know how build up process. In fact nobody can build a hull from zero as fast and as economic as we can.
We make well built concrete hulls available for even small budgets to start from there - we do not recommend acme intents that may be dangerous for the owner, harmful for the concept, and in best case end in expensive non working results. Do not re-invent the wheel, purchase a hull, get a proven concept.