TSI Volunteer Chris Rasch, who ran the Seasteading08 conference, has some interesting discussion about common objections to seasteading on his blog. He answer questions like "Won’t it be prohibitively expensive to live aboard a ship fulltime?", and "What about motion sickness?".
I’m expanding the FAQ to answer some of the comments made on the Marginal Revolution post, and I decide to start with a couple answers I should have written up long ago, because they are so frequently needed: