I think it will just be boats like JC, where some guide wheels hang down into that trough on rods. Thus, the boat can turn as sharp as the concrete trough turns.I brought the image into AutoCAD, and scaled it up with the assumption that the parking stalls shown are standard 9x18. I then threw in an approximate centerline through the flume:
View attachment 130075
According to my rough guesstimate, it looks like the track circuit is approximately 520' long. If we follow the assumption that omnimovers typically move at 1.5 ft/sec, that gets us a total circuit time of about 5:45 (keeping in mind that guests won't ride the full distance through the load/unload area)
For those of you playing along at home, the curve radii are 10-11', to help you approximate the scale you're looking at. The load/unload area is about 105' long
EDIT: The more I think about this, the more likely it seems that it will be the Shanghai POTC system. The normal iasw/POTC-type boats are roughly 8' wide, so it seems highly unlikely they would be able to make turns that tight in a flume (which would need an inner radius around 6-7', much tighter than what we're used to). Given that the Shanghai system's movement is unrelated to the vehicle size, it seems like a good match
They'd be propelled by pumps, like the other boat rides, rather than onboard motors.
Should give it a very free flowing feel to it.