Diving After Dark: By John Lidington

Wow!  We were already past February and I had yet to make a night dive in 2019.  But I finally got my schedule to sync up with an early evening tide at the Blue Heron Bridge and headed out to join one of Pura Vida Divers free night dives at the site and take advantage of a little diving after dark.  

Planning The Dive

The sky threatened showers most of the afternoon, a stiff SE wind was stirring things up a bit, and diving near the full moon usually means encountering a bit faster current during high tide.  Even in adverse conditions, however, the Blue Heron Bridge came through with another fine dive!

I started my trek from the west end of the beach, heading south.  I planned to spend the first thirty or so minutes checking out the tiny, well-camouflaged creatures that lurk in the sand.  Then, as the tidal flow slowed to slack high tide, I would explore the west side pilings for about an hour, and finally scoot back into the southern sandy area at the end of the dive.  I had a 100mm macro lens in my housing and hoped to find relatively small critters to photograph.

Close Encounters of the Cowfish Kind

Visibility was about 20 feet as I set out, with enough twilight left that I could pick out darker shapes on the bottom without a light.  As I finned into the light current, I saw something large crossing my path up ahead. Putting on a little speed, I caught up to a 14” Scrawled Cowfish (Acanthostracion quadricornis).  Not exactly the type of subject I was looking for with the macro lens, but I decided to take a couple shots just to see if my camera setup was working properly.

But this was a cowfish on a mission—none of the usual slow daytime ramble for him!  I managed to get off a couple shots as he made a beeline toward his appointment, but I quickly decided to look for subjects more appropriate to my lens.

Roving about over the sandy bottom turned up the usual cast of bottom creatures—sea cucumbers, starfish, and tube-dwelling anemones.  Then, while inspecting a lump of debris on the bottom, my light caught the reflection of a tiny eye. My first impression, as I moved in for a closer look, was that the eye belonged to a blenny.  The creature’s two-inch length and pair of cirri above the eyes definitely made it a blenny candidate. But something wasn’t right…

A New Discovery

As I moved around trying to get a better viewing angle to distinguish the fish from the bryozoans and algae in which it was hiding, I could see it was supporting itself on its large, flared pectoral fins.  What I was seeing appeared to be a tiny scorpionfish! Upon reviewing the shots I took, I think I found a juvenile Spotted Scorpionfish (Scorpaena plumieri). This species is common at Blue Heron Bridge, but I have never encountered one so small before. (Note, I would welcome any confirmation or refutation of this ID by those more knowledgeable.  The tail was too well hidden to give further aid in identification.)

At this point it was time to head toward the bridge’s pilings.  I trimmed my buoyancy, covered my lights, and drifted with the current.  I love to spend some time on every night dive with lights obscured. When they are on, it’s like having tunnel vision—I focus my attention on the illuminated area.  When covered, however, my perception seems to expand into all the dark space around me. The boundary between seen and unseen disappears. It’s a time to relax and disconnect for a few minutes…

The pilings sowed their usual variety of wildlife as well.  Parrotfish, angelfish, grunts and puffers put in an appearance.  At one point a group of divers came toward the piling I was exploring.  As they passed by on the other side, a huge Porcupinefish (Diodon hystrix) charged out over my head and disappeared into the night.  The highlight from this area was a Sharptail Eel (Myrichthys breviceps) probing the bottom for food. Unfortunately, like the earlier cowfish, he did not have time to pose, and disappeared into a hole in short order.

Midnight Munchies

Before too long I drifted out from beneath the bridge, following the flow of the ebbing (outgoing) tide.  Just after passing the cable, I spotted a strangely shaped white mass moving at the base a small scrap pile.  Checking it out, I found a Florida Swimming Crab (Achelous floridanus) proudly dragging a fish tail into his hideaway.  The piece of fish was as big as he was, so could probably keep him well fed for a couple days, if he could protect it from other scavengers.

My dive concluded with another frenetic creature encounter.  As I headed over the sandy bottom toward the beach, I spied a Giant Hermit Crab (Petrochirus Diogenes) hoofing it along below me.  Yes, hoofing it!

The giant hermits I’ve seen in the past tend to walk at a leisurely, if not a downright slow, pace. Maybe it was because this guy had a whelk shell instead of the queen conchs I usually see them wear.  Or maybe he had just returned from the Daytona 500. But he was really making time! I got him to pause for a quick portrait, and then he was off again into the darkness, and I headed in to shore with a fresh set of memories from another wildlife-filled dive at Blue Heron Bridge.

Explore With Us

Ready to adventure into the night? Join Pura Vida Divers for a paid guided dive or free independent night dives at Blue Heron Bridge, offered twice every month. Learn more about our Blue Heron Bridge night dive options here!