India, Sept. 14 -- It was 2 am my husband, Yash, and I were wide awake in our water-friendly tracksuits and Crocs, slathering mosquito repellent onto our skin in preparation for an enchanting nocturnal adventure. We waited in quiet anticipation in the lobby of Sea Shell Port Blair, nestled in Sri Vijaya Puram, the newly renamed capital of the Andaman & Nicobar Islands. Soon, a pair of torches bobbed through the darkness, growing larger as they descended the road that curves downhill towards our hotel. A small hatchback pulled up; its headlights dimmed.

The Trailblazer Bioluminescent phytoplankton emit natural light when disturbed, creating a magical glow on the water's surface. (Photo Credit: Shutterstock) "Morning. So nice to meet you,"...