Imagine a hexagonal grid of these between continents, with aqua-farms, data-centers, resorts, casinos, floating cities/solar/wind sprinkled in between. Err... Aqua-Loop?

Maybe 'grow' them 'in-situ' like corals, funghi, sponges, seaweed, algae, bamboo, whatever, by means of genetic manipulation.

edit: Not to forget, conduits for HVDC, ZBLAN, and all sorts of pipelinable stuff for the global super smart grid.

FUCK YEAH!

edding: Icebergs, yes, yes, Gridguards no less!