Ensign Ledo is a Machine Caliber pilot in the Galactic Alliance of Humankind,...
Gargantia on the Verdurous Planet
Season 1 Episode 9: Deep Sea Secret
Ledo and Chamber go deep-sea diving to exterminate Earth's Hideauze. After an intense battle they discover ancient video footage deep within a Hideauze nest at the bottom of the sea. The footage reveals Earth's former civilization.