We start at twilight, piling in the van for the bumpy ride to Mosquito Bay. We park in a sandy lot, and our guides ease the kayaks into the dark waters. “Don’t jump in,” Enrique instructs. While this bioluminescent bay has had thousands of visitors who have enjoyed a dip in the spectacular lagoon, the government is attempting to protect the delicate, microscopic organisms that glow when disturbed, so it doesn’t want people spoiling the water with chemicals and other toxins. Although my partner was born and raised in Puerto Rico, he’d never visited Vieques (a former U.S. military zone), and no trip to the tiny, 21-mile-long island off the coast of Puerto Rico is complete without a trip to Bio Bay, as it’s known. As we paddle out to…