None of the wet exhausts I've ever owned had that loop, but I have seen that described. Always just rose up up up, then down 1-2 feet at the exit.
One thing I never satisfactorily understood is how to figure out if your exhaust line is going to flood your muffler (and beyond, back to the engine) when you shut down. It seems figuring out just how much water is really in that line at any given moment is impossibly complex, it's some raging mix of exhaust and water...
On the other hand, usually your exhaust riser is up high enough to help minimize concern of reaching the engine
. I dunno..