4. Protection From Cataclysmic Events
Ever daydream about an asteroid hitting our planet and being one of Earth's last 'survivors'? Let's say a giant asteroid hits the Earth one day: it wasn't enough to produce a significant shockwave, but the dust from the impact begins clouding our atmosphere. What do we do for food now that the sun is gone? Life underwater would probably survive a lot longer than life on land. The reason is because of the underwater power generation methods available to us. Seaweed is known to depend on sunlight to go through photosynthesis. However, if we were to use the underwater buoys to power lights that could support seaweed; we'd virtually have an unlimited supply of food (given that the algae and seaweed have enough time to grow). Water could also be easily purified as the city is pretty much
covered in it. Humans could literally 'wait' the atmospheric dust off.