Idea : Add new creatures such as the Magnapinna squid, Collosal Squid, Anglerfish & others. You could also add coral reefs which have more creatures than normal and also have coral. Make it so that you can save an image from a camera and print it as a physical object in the game world (like a printed photo), you could also keep it as lua data.

Why : Exploring the deep sea is boring and it would be fun to find more interesting creatures.