ShipStead

The ShipStead is one of the types of Seastead. The key idea is that by purchasing an existing ship (for instance, but not necessarily, a cruise ship) we could eliminates R&D costs and the uncertainty about the costs and capabilities of the structure. This could make getting started easier. See also Patri's ShipStead project page.

Arguments In Favor

1. Ships are known to work fairly well on the ocean. They're somewhat survivable in large storms. They're relatively mobile, and that mobility can help avoid storms, visit more ports / countries, etc.
2. There are very efficient shipyards with lots of robots building cruise ships for reasonable prices.
3. You can buy used ships for reasonable amounts of money.
4. These could then be sold off as condos at reasonable prices.
5. Many seastead ventures like a Medical Business do not need a custom designed structure.
6. This could be a lower risk way to get an ocean safe seastead going.
7. Jeff Chan prefers the term "CondoStead" since a condo/timeshare is a familiar concept, easier to sell and explain, etc.
8. Essentially this idea is like Residensea / The World, but at a lower cost and with hopefully better economic structures.
9. A ship is much easier to pull into port, which is good for touring, repairs, resupply, etc. And they can also loiter in the open ocean fairly well. A spar may have a draft too deep to pull into port, so it may need to stay in the open ocean. With a ship, you can choose whatever combination of touring ports and camping on the ocean that you like. In that sense they are more flexible and offer more choices.

Arguments Against

1. Ships are not as radically different as a spar buoy, and possibly not as comfortable in large waves. Spars have much lower waterplane area than most ship types, though SWATH come close.
2. Spars may be better at staying on the open ocean than conventional ships. For example ships generally need to be in motion to be most stable in waves. Spars are designed to be more stable when stationary in waves.
3. Ships may cost more to build and operate than a series-production spar structure.
4. Steels vessels require regular maintenance of their corrosion and anti-fouling coating (paint) which necessitates dry dock. Ships that don't move quickly or often are subject to more biological fouling, reducing their structural integrity and increasing fuel costs to move, due to no longer being streamlined and efficient in shape.
5. It's not easy to raft or join ships together to form larger communities, though the same could be said for spar structures (or any vessels on the ocean).
6. A ship that stays in International waters is probably too boring to live on, but one that visits islands is probably no different than any other cruise ship. It could not have guns, drugs, etc.
7. Ships can only steer and have relative stability when they are moving (making way) and the stabilizers can work. If they were stopped in the deep ocean they would pitch, roll, and yaw much more than when moving. However, moving all the time burns up expensive fuel.