Seabases are your main center of operations in Subnautica. They’re a series of buildings/facilities that the player builds through use of the Habitat Builder tool, and provide you with an area to return to for oxygen, energy and also serve as an alternative to Lifepod 5 as a home away from home. Just remember to be careful where you place your new home! The deeper the depth of your seabase, the greater the chance that your hull integrity will be compromised, and you then run the risk of developing hull breaches. But, fret not! Hull integrity can be improved through construction of reinforcement panels, building your seabase on a foundation, or installing bulkheads.
Want to spruce up the place to really make it feel like home? Seabases can be customized through installing lockers, fabricators, benches, aquariums, and more.