Terror vs. Wonder: How a flashlight can make or break your night dive.

I call him, “the man in the gray suit,” and never speak of him if I’m diving. His name starts with a J, has four letters, and for eighteen years, he was the “great white” reason that my first night dive was my last.

I was tired and chilled from a long day of diving. I looked off the stern, watching waves wash across the entry ramp as the boat rocked in the swell. Getting in would be easy. Getting back onto the boat? Not so much. We gathered in the dark, zip-tied glow sticks to our SCUBA tanks, and anxiously checked our flashlights for batteries.

With hoods and masks on, it is hard to hear. So my buddy kept it simple, “Let’s go!” We were ready. I jumped overboard and felt my stomach float before I splashed into the cold. The black unknown beneath stoked my anxiety, turning it to a barely controlled fear. As soon as my buddy joined me, I gave a fast “down” signal, eager to stop bobbing helplessly on the surface. Going deeper didn’t help, though. Once I was on SCUBA, I turned my light on, and fear quickly got the upper hand. I could see what was in the beam of my flashlight. But the absolute inky blackness — above, below, behind, and around me — held every unseen horror I could imagine.

It didn’t matter which way I turned. I could see only what was in the light. My imagination created horrific predators invisibly streaking up behind me like fanged torpedos. I knew it was ridiculous. I told myself to stop. But I spun frantically, my light cutting across my buddy’s face, blinding him. And then — my mind now the enemy — the Jaws theme music played in my head and those predators got a name — one I do not speak. I gave in to panic — the most dangerous enemy in the ocean — and made a dangerous diving mistake: I abandoned my buddy.

I caught a glimpse of giant kelp ten feet below and swam for it, wrapped my arm around it, turned off my light, closed my eyes, and yelled into my regulator, “Just do it!” I was begging to be put out of my misery.

Recently, Christina and I were preparing our dive gear for a live-aboard boat dive in California’s Channel Islands. Christina casually suggested, “We need a couple of good dive lights. We can’t do the night dive without them.” The conversation stopped, a needle scratched across the record, and the disco ball stopped spinning. There was an awkward silence.

I tried to warn Christina about the man in the grey suit, told her my horror story, and hoped she would see reason. Instead she asked me what kind of light I’d been carrying. I was incredulous. What did the light have to do with it? I was talking about monsters, death, the horror of the unknown.

I still own that light, though. It’s too big and powerful to use in most situations but it’s an excellent dive light: it holds eight D-cells and a bulb that would be the envy of motorcycle headlights. I explained this. Christina laughed in the warm and reassuring way I have come to appreciate in my new dive buddy. “Carrying a bright dive light is like driving in thick fog with high beams,” she said. “That was your mistake.” She insisted I’d be more comfortable and see more, if I carried a smaller flashlight. I was skeptical. She was certain. So I agreed, secretly hoping the weather would make a night dive impossible.

After investigating the full range of dive lights from a brand we knew and trusted — Pelican — we decided to try their Nemo 2400 and Nemo 2410. Both take four AA batteries, and are about seven inches long. The only difference between them is the bulb. The Nemo 2400 uses an incandescent Xenon bulb, which puts out 45 lumens and has a runtime of 3.75 hours. The Nemo 2410 has an LED, which puts out 126 lumens and has a runtime of 7.5 hours. In addition to a longer battery life, LEDs last longer before burning out, and are more shock resistant. The lights fit comfortably in one hand, and the power switch is easy to flip with a thumb, even while wearing 5mm thick cold-water gloves.

It was a beautiful night, calm seas, no wind. There was no way of getting out of the night dive now. So I steeled myself to our dive, testing our new lights, and the terrors of the deep.

Underwater, there is a significant difference in the color of the light produced by these two bulbs. As much as I like the benefits of an LED, I was drawn to the warmer color of the Xenon bulb’s light. While noticeably dimmer than the LED in the Nemo 2410, the light from the Nemo 2400’s Xenon brings out the reds and oranges of anemones and encrusting corallines. Both lights illuminated the nooks and crannies among the rocks and seaweed that Christina and I wanted to explore, while leaving our eyes dark-adjusted enough to see all around us. Most notably, though, I made it to the bottom and was still interested in exploring those nooks and crannies. In fact, at my urging, we turned our lights off and swam by the light of the glowing nose-cones on the tip of the lights. The ocean blinked back at us as every move of our hands and fins triggered cascades of green sparkles in the water all around us. It was beautiful. In fact, it was the same ocean I had enjoyed during the day, just a little darker.

The only thing I don’t like about these lights is the wrist straps. I am going to swing by REI and get spring-loaded sliding cord locks to replace the sliding ring that comes standard for keeping the loop on your wrist.

Eighteen years ago, on my first night dive, the waves didn’t just make the boat uncomfortable, they also stirred up the bottom enough to make the water cloudy. Looking back, it’s easy to see that Christina was right. It didn’t take much suspended silt to turn the water into thick fog. My over-powered high-beam flashlight created a terrifying contrast between known and unknown and fueled that panic. As I clutched that slippery tangle of seaweed, the horror soundtrack slowly faded. Probably, in part, because I had turned off my light. Monsters never came. I looked up and saw my confused buddy wondering what the hell just happened. Rattled, nervous, and still blinded, I turned my light back on, swam up to him, signaled that everything was ok, and uncomfortably finished the dive.

Christina was also right that with a better light, it was possible to see while still leaving my vision dark-adjusted. We each had a reasonable beam of light in front of us, and all around us we could see the kelp strands rising like majestic shadows toward the surface, and we could also make out the contours of the rocky slope next to us. With the right lights, night diving went from a terrifying horror movie (with it’s own soundtrack) to flying through a forest scene in Avatar. I won’t lie to you… I was still nervous, but at least I could see, there was no scary music, and it will be a lot less than eighteen years before my next night dive.