Water-front real estate is valued at thousands of dollars per foot. One of the more optimal geometries to serve this market is the atoll. Artificial atolls can be tailored to specific markets in a number of ways, the most ambitious being "Exponential Remediation of Civilization's Footprint".
In general an artificial atoll will be a circular breakwater, surounding a lagoon of calm water of up to of 16-20km (10-12 miles) diameter.
Like in many natural atolls, people may live on small artificial islands, house boat, or floating tents, according to the taste and skills of the inhabitant.
The breakwater float on a toroidal tank containing a reserve a fresh water, which has lower density than saline water.
The seaside is covered by various types of coast type to maximize the diversity of ecosystem. The lagoon side is covered by rich topsoil covered of various plants and cultivation.
The bottom of the lagoon is open to the deep sea, but protected from unwanted predator by a net. Many forms of mariculture are practiced in box and other systems hanging at different depth. The low sea state of the lagoon may shelter floating photobioreactors producing algae as the base of the mariculture food chain.
The most ambitious