The first step in the Deep Sentinel program, one of the most ambitious ocean-engineering projects in decades, will be completed this year. This initial step, called Vanguard, will shelter three aquanaut-scientists at depths of 100 meters. Eventually, the project will create a modular underwater habitat system that will let scientists live underwater for weeks at a time.
Add in “But harvesting it angered the psychic primordial shark that we worship as a god.” And you’ve got the rough plot for the water planet from Kotor 1.