Of course, the whole "punk" genre started with the Cyber-punk. The idea was that so much of science fiction that dealt with the near future was pristine, anti-septic, and clean and that a more "roughed-up" version of life is more realistic. With movies like Blade Runner, you start getting an image of the future where everything is dirty. You've got trash on the streets. You've got dirt and graffiti on the walls.
Could you give us your definition of sailpunk? I could Google the unfamiliar term, but why not encourage a writer to wax eloquent? ;-)