We have yet to see if they are in any way the kind of Corsairs you guessed in your previous post. I guess they can't be all too horrible cutthroats or Marika's mom would never let her daughter anywhere near them, but I'd still say it'd be a stretch for the navy to automatically count them in unless from a purely tactical point of view (knowing they would defend the yacht club no matter what due to Marika and Chiaki being aboard). Even if they nominally are sanctioned by the government, they are still criminals with a criminal state of mind. They wouldn't be in such a business otherwise. A business of violent piracy.
Oh, well. At least I hope they are in such a business and aren't just some scifi born to be free space motorcyclists living on the edge but not being guilty of anything worse than vagrancy. That would be a letdown.