Hardly reversing' Those big diesel engine runaway's cannot be stopped. Unless you stifle the air with Co2 extinguisher. Which is why I carry one of those for my own old daf lorry.
Looks like it needs moving to the multistrada forum I know the authorities have been questioning whether ships so big, should be allowed to to use Venices very small waterways, this might help them decide
I was just giving anyone unfamiliar with a runaway diesel engine a bit of information. I'm sure a halon system could or should be designed into these size ships. Because a malfunction of an engine that takes control has to be stopped. And a way of stopping it is to remove oxygen from the fire-triangle.
Modern cruise liner like that is probably diesel electric with azimuth pods. Captain probably went backwards instead of forwards. They get a bit excitable on the bridge.