June 24, 2008


Vince Cate has written an excellent wiki page on Migration:

Imagine each seastead uses a kite and sea anchor to move in a big circle around the Sargasso Sea once each year. The currents are almost fast enough to do this, so even a slow seastead can probably make it. I am thinking Anguilla, Bermuda, Azores, back to Anguilla. We could time it so that we were in the North-Eastern half of this loop to avoid the hurricane season in the South-West and then in the South-Western half of the loop to avoid the cold stormy season in the North-Atlantic. With computers controlling the kites and sea anchors I think we can move at the right speed to make this happen. I think if we checked historical information that doing this you would never have had to face even a 30 foot wave in the last 100+ years. Designing/building for 30 foot waves is much easier than designing/building for 100 foot waves, so this type of migration could make the seasteads much more affordable.

Here are some of the things I like about the idea:

  • The lower the worst expected wave we have to design for, the cheaper our structure will be.  The cost of building something that can stand up to huge waves is one of our biggest concerns, so eliminating that would be a huge win.
  • A traveling sea colony will pass close to different countries and continents.  If we use the North Atlantic, like Vince suggests, we will get (relatively) close to the Eastern USA, the Caribbean, North Africa, and Europe each year.  This makes it easier to visit interesting places, and have them come to festivals we host.
  • It moderates temperatures by being in higher latitudes in the summer and closer to the equator in the winter.
  • Because it is following existing current gyres, and is very slow (< 1MPH), it should use relatively little energy.

We need more data to quantify the exact reduction in wave height (are off-season hurricanes nonexistent or just infrequent?), but this is a promising approach.

Also, this seems like a good place to make some meta-level comments.  Vince’s idea was useful because:

  • It was good.
  • It was written up nicely on the wiki, with graphs and data. The forum is a great place to discuss and refine ideas like this, but if they don’t get written up nicely on the wiki, they are liable to just get lost. So once you think an idea is good, please put in the time to write it up and put it in the appropriate categories / link it from the appropriate pages, so it becomes part of our collective knowledge.
  • There was some research behind it.  I’d had the idea of circling current gyres for temperaure and wave height reduction before, but I knew nothing about when hurricane season was, whereas Vince looked up the route in charts with gale probabilities to get some actual data.  So my version of the idea was just one of a zillion untested potential methods, whereas his actually had some vetting. That makes it vastly more useful, because we have lots of untested ideas and only the time and money to pursue a few of them.

We will be meeting with some marine engineering consultants in a few weeks to start the high-level design process, and figure out which structures are worth doing detailed modeling and analysis.  So if you have ideas for structure designs or features like migration which would substantially affect the design choice, please write them up on the wiki, and add them to the list.  Keep in mind our Requirements.