Yippie- look again, that's the waste port off the sand filter, lol. Moving water from under the cover to on top...
Rocket:. No "weight" to speak of on the cover - it's just floating on the surface of the pool. By pumping pool water on top I'm sinking it a couple of inches, but there is a ton of slack so no significant stress on the rails.
The cover pump sitting on top didn't make a difference - I think I actually heard the wind laugh at it. Once that cover inflates its really something to see. Usually only an issue if the wind picks up before I close it. Although if it gets up over 35mph it can start to inflate on it's own. The only way I've managed to force it back down is with water