Incidentally the WH2O I just purchased has this there, haven't removed it yet... Of course I won't move anything till I'm ready for a shop job.

Here's a thread I started on it way back when

https://pinside.com/pinball/forum/topic/white-water-wh2o-boulder-garden-layout

I have mine set up with a star post (and rubber) by the Boulder but I don't close off the area (the 2nd option in my post). I don't seem to get kickouts into the right outlane and it opens up the boulders for much more action.

That's how mine is.

I took mine out and it makes the game more difficult and I believe its how it was originally designed . The added post and rubber were added after testing revealed right outlane drains.

I think it was a late addition to prevent right outlane drains. I always left mine off and felt like that's how the game is supposed to be set up. With the rubber ring there, you never get any action from the rebound targets on the right side. Plus it makes the boulder garden too safe of a shot.

The rubber is there in the flyer, which probably means it was always designed to be that way, at least by the time it hit production anyway (note the playfield used in the flyer is from the early run with no water art to the right of the uper flipper)

http://flyers.arcade-museum.com/?page=flyer&db=pinballdb&id=852&image=2

I still like mine set up harder without the rubber there.

I removed all of it and then shrunk the right outlane as much as possible via moving the star post and slightly thicker rubbers. That balance seems to be fun for myself as well as my friends that play.

Thanks everyone for information on this. I've currently got a WH2O set up that I have borrowed from a fellow Pinsider and which has the rubber across the pop bumpers, and I was just wondering myself if this was a normal set-up.

I may try removing it to see what difference it makes in the gameplay.