Exeter's improvised gun control at the River Plate

How could Exeter's gunnery officer control fire while standing on a turret at the River Plate?

It was the only surviving observation position after the ship's normal control stations were shot through.

Exeter's exposed local-control position was not chosen for efficiency. Battle damage had eliminated both the main director and the ship's backup control stations, leaving the gunnery officer without a protected place from which to observe. Standing atop an 8-inch turret allowed him to watch the fall of shot and keep correcting fire despite the damage. This desperate expedient was possible with an 8-inch mounting in a way that standing over a triple 16-inch turret would not be.