Although living on  a private island is the ultimate way to live on the open seas, in the not too distant future people may be living on private islands but man made structures located below the water. One new proposal by UK-based designer Phil Pauley envisions a biosphere set in the ocean that would create a self-sustaining underwater habitat for aquanauts, tourists, and oceanographic life sciences. Made up of submersible spheres, the structure dubbed Sub Biosphere 2 would maintain and support life while acting as a secure underwater seed bank.