"Waterscraper" Seastead Underwater High Rise

From PopSci via eVolo via Geekologie, comes the idea of the underwater skyscraper called the "Water-Scraper." This design is one of the entrants in eVolo's contest for best futuristic skyscraper design. Water-Scraper received special mention.

Designed by Sarly Adre bin Sarkum of Malaysia, the waterscraper would be about as tall as the Empire State Building, but with only a couple of stories exposed above the surface. The whole building would be a self-sufficient, floating, arcology. Wind, solar, and wave power would provide energy, hydroponics and the green space at the top would provide food and oxygen, and the structure would provide housing, work spaces, and areas for recreation.
Ballast tanks would keep the structure level, like in a submarine, as would the tentacles. The tentacles would also move around in the ocean tides, generating electricity from kinetic energy. _PopSci

Al Fin naval architects state that this design is interesting, but that this single vertical structure would constitute only a fraction of the totality of a workable, large-scale seastead.

The Gyre design was similar in its lower vulnerability to surface waves and storms, but Gyre is more functional due to its outrigger pier and potential breakwater surface structures. The standard Clubstead design from the Seasteading Institute offers other advantages, including a small profile to waves. The half ship / half floating island designs offer the ability to move out of the way of very large storms, and to place your seastead in optimal locations according to the season.

A seastead must be esthetically livable, fully functional economically and commercially, and be survivable in the roughest conditions.

Ultimately, seasteads are likely to provide space launch, duty-free trades, financial services, specialty services for ocean explorers and miners, and Earth-to-space liason services. Every large space colony or mega-industry will probably want to operate a seastead as an independent Earth base.

It is clear that none of the conceptual designs thus far provides for all the needs of an all-purpose seastead. But at least a few people are beginning to think about what will be needed.