Just came across this submarine adventure game called Diluvion. Didn’t know much about it, so I did quick Google search and according to official Steam page
“Diluvion is a 3D deep sea, Jules Verne inspired, exploration game with RPG elements and thrilling submarine combat. As the Captain of your own vessel, you must grow and manage your crew as you search for the secrets of the past in a hauntingly beautiful flooded world.”