Settlements

“You’ll live your whole life with a roof above your head. If you don’t have a roof, life is short.” - Corin Hayes

Cities
The population centres of each corporation in which almost everyone lives. Usually built around a central dome, especially those cities in the photic zone/ shallow water, cities have grown over time. Some were planned, most were not.
The Dome of each city usually houses the wealthiest of the inhabitants, the upmarket entertainment centres, and the headquarters of the corporation or smaller companies. Living here costs money, but you’re close to the power.

Boxes
These were built and bolted onto the cities as they grew. As their name suggests they are usually cubes of accommodation. Small apartments, a bed and small living area, line every hallway and corridor. These structures are where the vast majority of people live. They contain levels where bars, cafes, shops and other amenities can be found. Some levels are no-go areas, controlled by the underworld gangs who don’t appreciate the presence of security or the military.

Communications
Cables crisscross the ocean floor connecting city to city, mine to settlement, factory to city and all the rest. They follow the shipping lanes, or rather the subs follow the cables to create the shipping lanes. Radio does not work under the ocean and a sub out to sea has limited chances to contact the city to get the latest updates. However, there are nodes along the cables where submarines can lower themselves to and collect data, make calls, or just gather the latest current reports.
Other than those, long distance communication is not a possibility.

There is a rumour that a few Corporations have some way to tap into to the old satellites, or even launch new ones, and use them as positioning and communication systems.

"The old moon-base conspiracy does the rounds every couple of years, but they’d still need a roof over their heads so if they’re up there, they’re no better off than us." - Corin Hayes