I really don't remember anything over the track when riding WL either, but remember some sort of ramp / stairs you went up going to the wave pool.
This doesn't really clear it up, but look at the picture at the top-right of this
1983 brochure. There's a fence of some sort to the right of WL's loop, with people standing there looking at the wave pool - and they're definitely much higher than the wave pool. I'm pretty sure that's part of the ramp you used to get to the waterpark.
Now, how did you get to that point? Perhaps you went under WL, like Scooby Doo's new exit, and the stairs / ramp I'm remembering is from when you came up on the other side. Or maybe you went under the back spike and around? It was so long ago I honestly can't remember the details. Hopefully one of the other old-timers will remember something.....
Those brochures on that site are quite interesting - there's others for Carowinds from 1987,1990,1999 and 2007. The first thing that jumps out at you is the prices on the older ones, but also if you look at the calendars you notice something else that's changed. Back then, Carowinds was closed on Fridays except July 4th weekend. I also notice that the 1983 and 1987 brochures made the place seem far more appealing than the 1990 one - which would've been after they removed White Lightnin' and had let Thunder Road go to it's natural color scheme.