Thus pointing out that most of the cost of housing on land is due to regulation, not due to supply. Urban growth limits are another idea conceived with good intentions that is easily perverted and generally poorly applied.
Consider the possibility that people build a modular seastead. They builld in a circle around a lagoon made of the modules. The first 10-20 modules have unfettered direct access to the lagoon, and also to the outside. After that, they have to start “stacking” them deeper. Some ‘originals’ may indeed be happy that they are getting a deeper buffer against the open ocean. Some may not want their view of the waves cluttered. Either way, they almost certainly charge a connection and access fee to anybody who wants to connect to them and traverse them to other modules or the lagoon. There are costs involved in designing and building for connections, after all. There are also opportunity costs involved in having one type of business or another next to you, and likewise with neighbors residing there. You want to have some kind of filtering mechanism that provides good neighbors (incidentally, this is known as a “barrier to entry” no matter who you are filtering for.) Once you’re 3 deep, you no longer have much control over who connects next. You’re also no longer as easily mobile as you were when it was just you in a ring around a lagoon. Over time, some areas of the assemblage gain a distinct character. Some more business, and some more residentially oriented. Some with lots of restaurants and entertainment options. People will find various degrees of desirability based on that character.
At some point, it makes sense to create another community, which means starting from scratch again with mooring and attracting a minimum number of people to support safety and services. Rinse and repeat.
The one thing that seems less likely to be a constraint on water than on land is inconvenient (for construction, but sometimes desirable for aesthetics) geographical features like slopes, hills, canyons, and river/lake boundaries. But the inference one has to make is that there is NO premium “land” or area which is naturally well-suited to build on; it’s all sub prime because it all needs a lot of work (in the form of building a platform) before it is habitable, like a sub prime piece of real estate needs a lot of fill or dredging prior to being useful. And that’s not to say that bottom geography is absolutely not a factor- you may moor fairly deeply but still run out of seamount platform within the necessary X hundred feet of the surface (depending on mooring design) Then you have an “urban growth limit” there as well.
Folks, I am ALL FOR this idea but feel compelled to poke holes in fantasies and rose-coloured thinking. Constraints don’t magically disappear with rainbow sprinkles on top of the water.
At best we get different kinds of constraints.These different constraints may be more favorable to our personal preferences. Economics is not about MONEY. Economics is about resources and human behavioral choices in allocating those resources. Economic principles are equally valid on land, in the water, or outer space.