Popsugar Entertainment Hbo Best HBO Documentaries | 2020 25 Powerful Documentaries You Can Watch on HBO Right Now 7 April 2020 by Hedy Phillips View On One Page Photo 9 of 25 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 United Skates Learn just how influential old-school skating rinks are on the world in this fascinating documentary about the skate scene. Watch United Skates on HBO. Previous Next Start Slideshow HBODocumentaries