Help Making Underwater Horror game!

I Have a plan to make a underwater horror game, it dosent have to be fancy since im new to unity. but what i want is to be able to

. walk along the seafloor (stay there only) except be able to jump up and float back down
.volumetric water feeling

so basically i want to be able to walk along the sea floor and shine a torch, but make it look like im under water (very dark) and if possible make it so i can only see couple of meters in front so it looks like water. any help with how i would do this would be good.

Well, it does not really need to be “underwater” Simply lower the gravity a bit, and your rotation on your controller and add some water’ish camera effects and make the fog close and dark in render settings. ^^