Besides tourism and jurisdictional arbitrage, there are a variety of other economic incentives to live on the ocean. Fishing and fish processing often involve employees spending many months at sea. Oil, diamonds, and soon a wide variety of other kinds of minerals are increasingly being extracted as land-based minerals are slowly depleted.
Gramlich and Friedman have a very admirable goal but are trying to do too many things in parallel. They seem to have spent far more time in creating futuristic designs from scratch than in figuring out how to retrofit normal ships or mobile offshore oil platforms. On top of this is their important but novel and ambitious political experiment in lowering exit costs. While there are some relationships between the politics and the engineering, a better approach is to innovate in one area at a time. Design novel offshore technology, or design novel offshore communities, but don't try to do too much of both at once.
Friedman voices a complaint, hardly uncommon in the world of engineering, that he has a hard time communicating with ocean engineers. I suspect the problem is that Friedman and Gramlich have taken their designs, whether workable or not, far away from the kinds of designs ocean engineers are used to analyzing. If they just started with normal ships and offshore platforms, then used such equipment as building blocks for larger structures, rather than trying to reinvent ocean engineering from scratch, they would not lack for experienced engineers to understand their designs and shops to assemble them.
Sure, such structures seem crude and inefficient compared with the elegant and optimal structures that might be designed in theory. But they would be a far less expensive way to demonstrate the political and economic viability of seasteading. And they could be shown to offshore engineers who could quickly recognize most major problems they might have. The Friedman/Gramlich approach excites the imagination, but a far more incremental approach is needed to make it work. To take up Friedman's analogy: if all that exists are military planes, and you want to start the first civilian airline, don't try designing civilian planes and civilian airports from scratch. Just buy a bomber, yank out the bomb bays and guns, install passenger seats, get permission to use a couple military airports, take a few test flights, and start selling tickets. The first version may well fall very short of the optimal or ideal you have in mind, but it will give you the experience and the revenue needed to improve the design and approach that optimal.
The biggest technological hurdle to meeting the requirements of the political experiment is probably the ability to join and separate the floating platforms at low cost. They must be moored and yet withstand the harshest storms (or alternatively to anticipate the storm, quickly unmoor, ride out the storm separately, and remoor when normalcy returns). This problem is mentioned briefly here but as far as I know, Seasteaders have not come up with a good solution for it.
Mooring in rough water is a hard problem -- there are good reasons docks lie in sheltered bays. Ship-to-ship refueling, a common naval procedure, has long been very dangerous in bad weather. Ships and platforms loosely moored with cables can easily collide, smashed together by wind and wave, with devastating consequences. Friedman and Gramlich believe that their ideal platform will have "no" bobbing, lateral movement, or tilting from waves and wind. But oil platforms do exhibit enough such movements that trying to keep them moored together with traditional techniques in a storm would be highly dangerous. Cables could not prevent the platforms from colliding with high force, whereas a completely rigid mooring that coupled the movements of all the joined platforms would likely fail from strain.
Some good old Internet searching digs up the fact that folks in the deep sea oil and liquified natural gas (LNG) industries have solved a similar problem -- how to offload fluids offshore, from FPSOs to tankers or from tankers to offshore pipeline terminals. For example the LNG industry needs to be able to hook up the huge LNG tankers to the offshore offloading terminals even in storms. One solution to this is the soft yoke flexible mooring. This is often abbreviated "SYMO" for "soft yoke mooring and offloading". It allows ships to moor to each other without the dangers of approaching and colliding in rough wind and water.
A soft yoke flexible mooring (SYMO) for yoking ships together, even in rough waves and most storms. The design allows each ship to ride the waves separately, greatly reducing the strain on the yoke, while keeping them from approaching or dispersing.
Here's how I might do an experiment in offshore political mobility using off-the-shelf equipment or minor variations on same (this "mixed" version, as the Seasteaders would call it, is not terribly original to me, except for including a workable mooring technology):
(1) Get a few dozen yacht owners to participate as volunteers. ("Yacht" here just refers to any seaworthy boat capable of mooring to other such craft and to larger platforms with SYMOs).
(2) Set up a system of two or more privately owned offshore anchored moorings: tough cable moorings such as those used by large ships in the oil industry (eg FPSOs).
(3) Attach a small old cruise ship or retrofitted oil platform to each anchored mooring. These should be large enough to have most of the infrastructure a small cruise ship would have, and be able to provide basic services to the yachts.
(4) Yachts moor to the larger ship or platform using SYMOs. For oil platforms the SYMOs may have to be heavily modified. Yachts might also moor to each other using SYMOs, but some of the yachts should also be anchor-moored to the ocean floor, unless they don't mind the community drifting.
(5) Yacht owners choose which of the two or more communities they will join.
(6) The cruise ships or platforms that form the core of these communities compete to provide various services, amenities, and political systems.
(7) Yacht owners can either be independently wealthy, or they can make a living by providing services to nearby fishing fleets, fish processors, offshore oil platforms, etc., or by providing temporary quarters for workers of same.
(8) When a storm comes that may be too much for the small SYMOs to withstand, everybody gets on yachts and disperses until the storm blows over.
These communities would look a bit like this offshore floating dock in a sheltered bay near Lund, British Columbia -- but much farther offshore, larger, more robust, and more politically independent.
If you see this coming, scram.
There will be big differences between these salty communities and modern towns. If the local court or zoning board or captain-of-captains won't approve improvements to your yacht, or your desire to set up a gambling house or a stinky fish processing plant, just move your house to another seastead community that will tolerate it. (I suspect fish processors will retain their own separate communities). Low exit costs bring freedom.
One kind of public nuisance that these seasteads may be in special danger of running into is what I call a provocative externality, meaning that besides or instead of being ethically dubious or causing direct harm to the community, they may cause danger to fellow community members by provoking a country to attack the seastead: drug smuggling, money laundering, polygamy, being a haven for terrorists, and so on are examples of activities that could, whether rightly or wrongly, provoke attack. Since many of these activities might also be quite lucrative, the political issues of whether to ban them may cause great tensions. Vulnerability to attack by traditional countries limits the degree of substantive liberty seasteads can achieve -- they will not be able to achieve a perfectly voluntary society within even the substantive law, much less within procedural law, which I now turn to.
The political and legal designs for Seasteads need even more work than the engineering designs. It is not enough to just say that all law be based on contract and thus all will be fine. One must rather tackle crucial issues such as legal procedure. As I have written elsewhere, in response to a claim that Seastead government will not be based on coercion:
No coercion? In these Seasteads, who does the law enforcement, and who or what gives them the right to commit law enforcement acts that are physically equivalent to torts and crimes? What distinguishes arrest from assault and battery, imprisonment from kidnapping, legal distraint of goods from theft, or a legal search from trespass? I think you will find that these societies will have to deal with the very same problems of coercion and procedure as our own governments. Calling a legal document that defines and allocates rights to commit these coercive acts a "contract" instead of a "constitution" may be the Rothbard-correct way to do things, but it doesn't actually go very far towards solving the hard problems of living together in a world where people are often coercive.It is even more important for the political and legal designs than it is for the engineering designs to take an off-the-shelf approach. Pick a country and subdivisions thereof, either a current or a well-document historical politican and legal system (for example the U.S. and a particular state, county, and town), and use its constitution, statutes, and court precedents as basic legal precedents, which can then be modified by local courts (in a common-law manner) and other local political authorities. If the U.S. is used as a model, I have suggested some basic changes to make its constitution less subject to the growth of government power. Low exit costs will also greatly help. These kinds of macro-political issues will mostly, however, be well beyond the scope of Seasteading unless or until they reach a time when they are large and mature mobile cities. The first ones will, as with cruise ships today, probably just be based on the "captain is king" model that has long dominated sea law. Friedman has even taken to calling himself "Captain Patri". Perhaps seasteads will revive the old paradigm of political property rights. I wish these projects the best of luck.