When you are finished with the design, you get to do a second set of calculations to move it from land and launch it in water. That's what naval architecture is all about. Naval architects go through the same level of architectural training as their land-based counterparts with more emphasis on structural, mechanical and electrical engineering. The State of Washington has a professional engineering registration system governing these activities under the same rules as land-based architects and engineers. Arrangement of the living, working and support space is sometimes more critical in naval architecture.
Real estate is very expensive, because the naval architect has to create it.
Imagine building a structure on an island, but first having to build the island. It is a space utilization challenge to make a comfortable, livable environment that is streamlined for efficiency but not too large to impact cost. The standard Uniform Build-ing Code is replaced by use of U.S. Coast Guard regulations and Classification Society rules such as the American Bureau of Shipping, Lloyd's Register, Det Norske Veritas or French Bureau Veritas. References are still made to national and international building codes that keep a measure of uniformity between the land and water rules, but sometimes are at odds with international regulations. Typical seismic structural analysis and AISC rules are also in the naval architect's tool kit.