Underwater houses for sale in Dubai.

The $2.8 million Floating Seahorse is the product of more than 5,000 hours of research and 13,000 hours of design and engineering, according to design firm Kleindienst Group.

The first models went on sale last year, before any Seahorses were even completed. Kleindienst says it sold approximately 60 Seahorses in 2015. More are still for sale.
The underwater portion, composed of a master bedroom and bathroom, will make up approximately 270 square feet on the interior. Just outside the walls is a 500-square-foot coral garden.
From the home, residents will be able to see actual seahorses dance through the Arabian Gulf — the animal's natural habitat.

The floating homes will have a massive floating bed as well as an observation deck above water.

If you want to take a swim, a convenient step-ladder offers a safe entry and exit. Or you could just dive right in.
Since the structures are located about two and a half miles from Dubai's shores, inhabitants can reach their Seahorse via boat or seaplane — not exactly the most accessible way to get to and from home. Once they're out there, they can cross between the islands via floating jetties.
Kleindienst also hopes it can make some headway in restoring the endangered seahorse population in the area.
"We will create an artificial coral reef beneath the luxury retreats which will be a protected area in which seahorses can safely live and breed," Kleindienst said at an unveiling even in May 2015.
Follow-up phases, including islands outside The Heart of Europe, will take place in 2017 and 2018.
With demand already high for the Floating Seahorses, Kleindienst says its next stop are the St. Petersburg islands portion of The World.

Part of that upcoming phase will be even larger, $12 million Seahorses, which are designed for families and groups.

The so-called "Signature Edition" homes will include more than 4,000 square feet of space over the three floors.
They'll have four designated bedrooms and several rooms that can transform into sleeping quarters, meaning the Seahorse can accommodate up to eight adults and eight children, according to Kleindienst.

These bigger structures will feature complete smart home automation, even down to the blinds.

Below the water's surface there are actually two bedrooms, one bathroom, and a viewing area for the coral garden. 

There will be nearly 900 square feet of living space and 600 square feet on the outside of the Seahorse for the garden.

Business Insider UK.