Humanity now lives on a moon called europa after Earth is not habitable for long periods of time.In order to get oxygen they use giant space tubes connected from Earth to europa

In order for it to be clean it goes through thousands of different filters that do different things to insure that the air is clean for every one once the air is filtered it goes into one giant tank that is connected to dozens of tubes that lead to different parts of the city so that everywhere has oxygen,in order to keep the oxygen in the city every city is in a giant dome,and that is how the city's get their oxygen.Next is jobs,of course there's hundreds of jobs to choose from but there are 3 jobs that pay the highest, the first job and the least paying of the 3 requires you to stay on earth for about 5-10 days before going back to europa to take tests to make sure you healthy before taking a 3 day break, this job is making sure that the the tubes are safely connected and that they're delivering a steady stream of oxygen to europa.

The second requires you to live in small dorms on the tubes 5 days a week before taking a 2 day break,this job is about making sure that the filters are working properly and doing their job and the reason this job is the second highest paying job is because if a crack appears in the tube it will be destroyed and the city's connected to it will suffer huge casualties

If. A city's oxygen supply is cut of there's always reserves that last about 48 hrs for them while they deal with rebuilding the tube

The third and highest paying job and what this series is about it is deep sea diving why? You may ask and the reason because the surface of europa is ice 10 miles thick that is floating on an ocean that is 100 miles deep

So far humanity has created the technology to travel 30 miles deep but after that going deeper is dangerous but worse there are alien sea creatures In there and every single one is deadly and can kill you the largest creature found was a giant gold fish that was 1 mile long and and 1 kilometer thick with teeth 10 metres long the deep sea diving squad were all eaten by it except for the one inside the submarine oh yeah guess I should tell you that divers don't swim from the surface to their destination they use submarines and explore once they get there

Now it's time to tell you about the plot,

Damian miles always wanted to be a diver and now he just got accepted to the most prestigious divers academy in the city Oceana or "the city of diving" join Damian on his journey to explore the ocean and discover new species.