Level 7 - "Thalassophobia"
"The darkness of Level 6 fades and a house enters your eyesight. It's flooded and it's basement is your only ticket to the cave..."
Description

What awaits you after the darkness fades.
Level 7 starts off as a generic house almost completely flooded with cold water (below 10 degrees celsius) with some of the furnishings of the house actually being fully submerged in it but these are typically the smaller objects. The water itself is no deeper than about half a meter but it is present throughout the whole house no matter where you go.
Lighting in Level 7's house is about as bright as a house during a spring afternoon and the temperature around the house is roughly the same as the water you will be treading through. The house is also the safest point within the level, and if you can't swim the staircase to Level 6 is just behind you in the room you will start off in.
The Waters
The Second Floor
The basement of Level 7's house is entirely flooded and will require one to swim down into it to get deeper into the level. From this point onward, there will be no oxygen within the level so take a good, long final breath before advancing beneath the basement's waves… (there is a property in the water that lets you hold your breath for a bit longer though). After the dive, you're now in "The Daylight Zone" and the water now looks exactly like that of an ocean. The lighting is bright but the temperatures remain cold. This section is completely empty, devoid of anything.
About 1000 meters below The Daylight Zone is "The Twilight Zone". Here, the lighting is significantly darker and the waters are significantly colder (now less than 6 degrees celsius). Once again, this section is entirely devoid of a single thing apart from you of course.
4000 meters below The Twilight Zone is "The Midnight Zone". In this zone, things begin to get incredibly dark and incredibly cold. Still devoid of anything.
8000 meters below The Midnight zone lies "The Abyss". The Abyss is pitch black and temperatures are freezing. After swimming for a whole, you will eventually notice that the water fades into a small lake in Level 8.
Entrances
A staircase in Level 6 with the sounds of water.
Submerging completely in any pit of water can lead to one remerging here.
The Hub if you have its key.
Exits
The Abyss will fade into Level 8 after a while. Only exit.