I didn’t know we’d be paddling through mangroves. And that it would be almost pitch black. Now, after getting stuck in the roots and dangling branches, it made more sense why the guides warned us that people fall out of their kayaks — even though the water is calm. And that I shouldn’t bring my digital SLR camera — even though I tied plastic grocery bags around it to protect it from the water.

Lest you think I’m a newbie kayaker, I’ve done two multiday paddling trips, both while pregnant: one unguided five-day trip between the Everglades’ mangrove islands, the other circumnavigating La Espiritu Santo in the Sea of Cortez.

But I’ve never been so disoriented as I was during the 45-minute paddle to Puerto Rico’s Laguna Grande, one of the island’s three bioluminescent bays. It was like kayaking while blindfolded — I couldn’t see any better with my eyes open than shut. The only real light was occasional red flashes from signals on the kayak sterns. Until we got stuck, I didn’t even know we were near mangroves. I thought we had entered some kind of tunnel.

Obviously I hadn’t done my homework. My 10-year-old daughter Dori shrieked as she hit the low-hanging branch from the kayak bow. The guide silently glided over to free our boat from the branches, shining his flashlight, which allowed me a brief moment to glance around at the surroundings.

We booked our trip purposefully for a new moon night, so that it would be even darker, to more easily see the glowing dinoflagyllates in the water below. While we started to see the oar light up in the brackish mangrove waters, I was so busy paddling and steering, trying to avoid the boats in front of me and the returning kayakers on the left side, that I couldn’t look down and appreciate the view.

Finally we entered the lagoon, making a side-by-side flotilla with our group, so the guide could talk about the bioluminescent bay. The waters here are filled with the prehistoric one-celled organisms, half animal, half plant. When disturbed, they glow like fireflies. I felt like I was on the Pirates of the Caribbean ride. When we dipped the paddle in, it lit up, outlined like an X-ray. Cupping the water in our hands, it looked like we were holding sparkling pixie dust. Even after the initial glow subsided, the water looked like it held twinkling stars. To say it was magical sounds clichéd, but it was true.

The dinoflaggelates thrive in Laguna Grande partly because the nature reserve has limited pollution. Swimmers are no longer allowed. Sunscreen and bug repellants containing DEET were killing off the very organisms people wanted to see. The mangroves that almost tossed us from the kayaks help the organisms thrive, releasing vitamin B12 into the water. This, along with the sunlight, help them live and grow.

Spanish explorers during the 17th century thought the water was the devil’s work, and they tried to kill the organisms by putting rocks at the mangrove entrance. This had the opposite effect, increasing the available food and maintaining the favored warmer water temperatures. These tiny organisms live only five days, reproducing at three days.

We were allowed to dip our hands in the water and splash about with the paddles.. While my daughter did what she was supposed to do, appreciating nature by playing with the water, I tried taking some pictures with the albatross, er camera, around my neck. It didn’t work. I needed a longer exposure and no movement, which I wasn’t going to get with a 10-year-old in the boat.