Propulsion

How to keep a Seastead in place.

• Mooring
  • Permanent anchor
  • Sea Anchor
    • Sea Anchor

How to move a Seastead.

• Motor powered
  • Thrusters
  • screws (steam, oil, nuclear...)
    • Azipod
    • Voith Schneider Propeller
  • Paddle Wheel
  • Water Jet

• Wind power
  • traditional (sailing)
  • kite
    • SkySails
    • KiteShip
  • Flettner rotor
    • http://www.magenn.com/about.php

Flettner's spinning bodies are spinning vertical cylinders, which propel the vessel thanks to the Magnus effect.

• Current

The Magnus effect can also be used with the sea current. If the Seastead spins while in a current, it creates a whirlpool of around itself, and experiences a force perpendicular to the line of motion and away from the direction of spin. As far as I know, there is no application of this to water current, although the Kutta-Joukowski theorem states the force is proportional to the density of the fluid, that is 60 times larger.

How to keep a group of Seastead together.

If a group of Seasteads just want to stay near each other but not bump into each other while they mostly drift around a gyre, then kites and sea anchors could be enough. The right kind of kite can pull to the left or right of downwind by something like 75 degrees, or any angle in between.