We are out, exploring the night life in Havelock in the Andamans. It is different. In complete darkness, the powerful shaft of silver from our flashlights picks out the creatures of the night: a languorous lobster here, a bunch of spindly shrimps looking like rock stars, a squid there, spiky sea urchins littered across the ocean floor, a brilliantly hued parrot fish in slumber under a massive rock. Butterfly fish at Narcondam, an isolated island in the Andamans We are about 15m under the Indian Ocean, exploring a coral reef on a night dive. Before we surface, we stop and turn off our lights. It is like switching off the universe. Nothing is visible. There is no sound. All sense of direction and dimension is erased instantly. We could be floating in nothingness. Then we do what we have been itching to dowe give the inky water around us a quick swirl. It comes brilliantly alive. The water is instantly speckled with the magical blue-green bioluminescence of microscopic plankton....