one of artist jason taylor's underwater sculptures in grenada, west indies.
his concept for this process is fascinating:
"An underwater gallery creates a whole new perspective on the world. Submerged objects are affected by different conditions both physical and emotional. Objects appear 25% larger and closer, colours are changed as light is absorbed differently by the water. The surface of the sea creates an ever-changing kaleidoscope of light, whilst its turbidity acts as a filter. The aquatic medium affords the viewer a multitude of angles and perspectives and thus transforms the traditional role of passive observer into an active process of discovery and engagement.
The ocean provides a setting imbued with mystery. Observers are invited to appreciate the works of art whilst questioning their circumstances and history. The viewer is immediately committed and involved to the environment and becomes part of the work itself. The sculptures will be an ever changing exhibition as nature colonizes the surface and the sea and tidal movement shapes the texture."
here you can follow the steps it took to get the sculpture created and put at the bottom of the sea.
in addition, this little video is really worth watching.