system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do airplane black boxes have to be kept in water after they are removed from the sea?

Following the latest Lion air plane crash, I saw a video of the black box being retrieved. Upon taking it out of the water it was immediately thrown and kept in a bin of water.
gpt
Black boxes have to be kept in water basically to avoid corrosion.

Let’s say the plane crashed into the sea, and the black box was drowned in salty sea water for some time. When retrieved, it will be thrown immediately into normal water to avoid corrosion so the people will have more of a chance of recovering the data.