After watching a Orlando and Hollywood, I stand corrected (of course I've never seen Hollywood) it does appear to have some sort of breaking system that brings the boat to a stop so it takes the turn slower, it looks like the final run is shorter than those of Orlando. However, Orlando does not have this system.
Further, I can see the two tracks that the boats "sit on" during the ride. However, I still think there may be some space between those two tracks where you could maybe sing under. Of course I'm not sure, and it might not be possible.