What did a battleship gain from a spotter aircraft?

Was a battleship's seaplane worth carrying?

In theory it improved long-range spotting and fire correction, though real-world effectiveness was less consistent.

The aircraft did not aim the guns itself; it observed fall of shot and transmitted information back to the ship's fire-control team. Its elevated viewpoint could extend observation beyond what the ship could see from near sea level. The team aboard still had to process those reports into corrections and a firing solution, which made results less consistent than the theory suggested. Spotters could also drop flares and perform other observation tasks beyond correcting gunfire.