May I suggest some further reading?  Two Years Before the Mast, The Way of a Ship by Lundy, The Proving Ground by Knecht.  The ocean is not a benign environment. 

The use of "flags of convience" is not a defence.  If this is a resort, that's one thing; but if you're producing something of value you will have to protect it with something more substantial than an international court of law.  Especially if it's Waaaaaaaaaaaay out there........

 Buck Norton

I think tidal waves only manifest on land. Tidal waves and such can travel across oceans but they are mostly pressure below the surface. The big wave develops as this force impacts landfall and starts to literally climb up it. I think these folks would worry about hurricanes but engineering-wise it's common for structures at sea to withstand them.

>> Or maybe you are Japanese?

 Could be. 

Still, I noticed the article did not address what are very real possibilities.

It's funny that you can spell tsunami, but not tidal wave. Maybe repeat second grade? Or maybe you are Japanese?

The Seasteading Institute is awesome. 

Words like Tsunami and Tidlewave and Hurricane come to mind.