FOR centuries, humanity has viewed the ocean as a metaphor for infinity. The assumption was - and frankly still is for many people - that the enormity of the sea comes with a limitless ability to absorb and metabolize all. This vastness is what lends the ocean deity-like potential. And more dangerously, it is what has given humans the license to dump virtually anything offshore. Oil, sewage, corpses, chemical effluvium, garbage, military ordnance and even at-sea superstructures like oil rigs disappear into the oceans as if swallowed up by a black hole, never to be seen again.