Boy escapes fire on ship down elavator and ends up in a hostile miniature city patrolled my drones

Hi Everyone

I’ve been struggling to find the name of this movie for years.

There is a fire on a ship or submarine, before it is destroyed, a boy manages to escape down a type of elavator
that lowers him underground or underwater. He seems to be going down for a while. When he gets out, there are patrolling drones, which he hides from as he makes his way through undetected.

I remember a scene where the boy was walking past some buildings, like miniature skyscrapers. The boy could see over the top of them and was hiding from some of the drones. I don’t remember if they spotted him and attack and he tries to escape.

Unfortunately I didn’t see it past there, as my Mum made me go to bed 😆 (it must have been 25 years ago when I watched it, I’ve been randomly haunted by it since!