Tarpons are big fish, with some measuring more than eight feet long, and they are eerily industrial-looking with glassy eyes and shiny scales that give them an armor-plated appearance. They are undisputedly at the top of the food chain in Bonaire (Netherlands Antilles), where they dwarf the barracuda, and sharks are scarce. These prehistoric predators spend their days hanging motionless under ledges or manmade artifices like shipwrecks and piers and do their hunting by night. This can make for a thrilling and sometimes unnerving experience when diving after dark.


As the sun dipped below the horizon, our small group slipped into the water off the beach just across from Flamingo Airport’s sole runway. KLM’s nightly arrival roared in just over our heads, bringing hundreds more European divers to this arid speck of diving paradise in the southern Caribbean. We switched on our underwater lights and kicked out toward the reef 100m from shore. I pressed the lens of my light against the sapphire crystal of my Panerai Luminor Submersible and held it there for 20 seconds. When I removed the light, the dial markers and hands glowed with nuclear intensity, living up to the Luminor name. I twisted the bezel to align the descent marker with the minute hand and kicked hard to catch up with the group, which was rapidly disappearing into the darkness.


Like the tarpons, Panerai’s Submersible dive watches also have an industrial appearance, their singular purpose apparent even to a casual observer. At 47mm, these watches make no illusion that they are intended for topside diversions. In fact, the massive size, with which Panerai arguably inaugurated the oversized watch trend, follows the specification laid down for the original Panerai dive watches of the 1930s and ’40s by the Italian Navy — large, legible under all conditions and extremely water-resistant. There is a certain steampunk aesthetic to most of the watches from Officine Panerai. The stenciled-out sandwich dials and half-moon crown protection device look whimsical and stylish, yet brutally functional at the same time.

The earliest Panerai watches, which can lay claim to being some of the first purpose-built dive watches in existence, were studies in minimalism. They had cushion-shaped cases with welded strap bars, sturdy handwound Rolex pocket-watch movements, and lacked even a sweep seconds hand. Yet they were procured specifically for use by Italian military divers embarking on some of World War II’s most daring and dangerous underwater maneuvers. With the modern Submersible line, Panerai added the element of a rotating elapsed-time bezel, which has pretty much been de rigueur on dive watches since the early 1950s. Before that time, divers would pop the crown of their watch out, set the minute hand to 12 o’clock and push the crown in before descending. In this way, they could track their bottom time, at the expense of knowing the time of day. Whether the early Italian combat divers used their Panerais in this way, or just to coordinate rendezvous times, is not known. But in 1956, Panerai added a rotating bezel to its watches for the first time, on a monstrous 60mm Radiomir model created for the Egyptian Navy.

The bezel on the modern Submersibles is directly descended from this first “Egiziano”, with a rounded profile, polished coin-edged outer rim and raised five-minute markers. Night diving is disorienting. Navigating on a dive can be a challenge even in daylight, due to the 360° nature of the environment. But at night, your world is reduced to the cone of light from your handheld torch. It is not unlike walking in the woods at night with a flashlight. In Bonaire, the reef wall runs parallel with shore, so the trick is to use a luminescent compass and swim straight out from shore to the reef and then turn one way or the other, and keep the reef on one shoulder going out and the other coming back. Landmarks that are useful during the day are nonexistent at night. Then again, it’s worth it because a whole world of sea life wakes up after dark — octopuses roam the bottom like ghosts; pale spotted eels that look like vipers slither among the rocks; and the coral itself wakes up, waving fronds to catch fish eggs floating on the current. And the tarpons are out hunting.

The Luminor Submersible 1950 3 Days, known more commonly, and succinctly, by its reference number, PAM 305, follows a string of preceding Submersibles that varied by depth rating, case material, dial configuration and size. What immediately distinguishes it from the rest, at first glance, is its dial, which, rather than featuring Panerai’s familiar rounded numerals, relies on more sober hash marks and dots. The dial itself is a matte black and, upon closer inspection, is found to be of a bead-blasted finish, which continues the watch’s almost severely functional appearance. The date cutout is no-frills also, a simple rectangular cutout in the dial revealing the number beneath; no magnifier, no finely beveled window. This is a watch that means business, and Paneristi who think their favorite brand has strayed too far from its “tool watch” roots need only look to the PAM 305 for reassurance that it hasn’t.


At 47mm across and close to 18mm tall, I expected this Submersible to be a chore to wear. But the sculpted “Luminor 1950-style” case with its relatively short lugs and smooth corners lies nicely on the wrist, and more importantly, the use of titanium as a case material keeps the watch downright comfortable. The PAM 305 comes fitted with one of the beefiest rubber straps I’ve ever seen. Lug width on these watches is a whopping 26mm, and the strap itself is extremely thick and sports Panerai’s massive bottle-opener buckle. The strap is of the vented variety, with accordion-style ribs near the case. These vents serve to take up the slack in a compressed wetsuit underwater. Pull the strap tight over a neoprene sleeve to stretch out the vents at the surface, and as you descend and the sleeve shrinks due to water pressure, the vents relax and take in the excess. The strap also lends the watch further diver credibility — as if it needed any more. I sense my first tarpon before I see it.

Even underwater, there is the primal sixth sense when something big is nearby. Sure enough, mere feet away, a meter-long tarpon silently cuts across my beam of light and I draw on my regulator in a sudden, startled gasp. His silver scales shimmer in the reflection and there is an eerie prismatic effect to his large eye, bouncing a vector of green light as he scans the reef. The big fellow is hunting by the light of my torch. Small fish scatter and dart for the safety of coral heads as the silver giant cruises slowly, but watchfully, overhead. By now, we’ve all seen the tarpon and it’s not just one. Two, then a third, appear out of the gloom, crisscrossing in front of us, brushing alongside us like a pack of dogs that has taken us on its nightly excursion. While we came for the eels and the octopuses, now we can’t take our eyes off the tarpons.


Of course, the feature for which Panerai is best known is the levered crown guard that is screwed prominently to the side of the Luminor case. While this may have been an innovative solution in the 1940s when it was introduced, it seems oddly superfluous and inelegant for a dive watch in an era when screwdown crowns are ubiquitous and nearly fail-safe. But the crown guard has become such a symbol for Panerai that it would be sacrilegious to remove it from the Luminor watches. I got over my skittishness about diving with a watch without a screwdown crown and learned to love playing with the locking lever, even though the watch is self-winding and there’s little need to manipulate the crown other than to change time zones en route to the Caribbean.

Historically, Panerai was a maker of luminous instruments for diving and their expertise was in rugged cases and highly legible dials. They played to their strengths for decades and when the navy came calling for watches, Panerai naturally turned to the best watchmakers available, across the border in Switzerland, sourcing from Rolex and Angelus. Even into the 1990s, Panerai followed this tradition, fitting its timepieces with venerable ETA movements such as the 6497-1 pocket-watch caliber and the ubiquitous Valjoux 7750 chronograph works. It wasn’t until fairly recently that the brand started creating its own movements in-house. The self-winding movement that powers the PAM 305 is the P.9000, a relatively entry-level in-house caliber, if it can be called that. Besides a date function, there are no further complications, and the finishing of the movement is decidedly Spartan. While the bottom plate, visible below the balance assembly, is perlaged, most of the movement is hidden from view, and the top plate and weighted rotor are expanses of brushed steel. It is a fitting lack of flourish for such a utilitarian watch’s movement, and in fact, I would have preferred a solid titanium caseback on this behemoth to keep with its functional aesthetic.

One handy feature of the P.9000 is its ability to advance the hour hand independently. This allows one to change time zones without having to hack the movement, though changing the date is a bit more work since it requires spinning the hour hand through 24 hour cycles until the correct date is displayed. The three-day power reserve is reassuring, though I have always found that long power reserves were more useful on hand-cranked watches than automatics that stay wound as long as you’re wearing them. It is one thing to watch animals hunt. It is quite another to actually help an animal hunt, to be drawn into the predator-prey dynamic and tilt the odds in favor of the hunter. I felt a twinge of guilt as I aimed my light at a small silverside caught out in the open, its whereabouts suddenly laid bare to the pack of swift tarpons. A scaly giant gave chase as I illuminated its prey until the moment of capture. With no acknowledgement or gratitude, the big fish lazily turned and resumed its endless quest for calories, made easier on this night by these air-breathing aliens with their torches. The game continued for another 15 minutes, tarpons zigzagging in and out of the blackness, following our lights as if on leashes. As if navigating isn’t challenging enough at night, keeping track of one’s time, depth and remaining air pressure is also difficult while night diving. On one wrist, I had strapped on a digital dive computer and, next to it, a compass, both with luminous dials. My submersible pressure gauge, also with a glowing dial, was linked to my regulator and hung clipped at my waist. All of these instruments require regular charging up of their lume using a dive light — after which, they burn brightly for a few minutes before fading to a dim glow.


However, on my left wrist was the Panerai and its dial and hands still glowed brightly 30 minutes into the dive, as indicated by the lumed pip on the bezel. Though we all had well over half a tank of air left, it was a good time to turn for shore. I charged up the lume on my compass with the dive light and reoriented myself. The tarpons, now accustomed to our hunting help, followed us like faithful labradors, weaving in among us as we finned for home. As we neared shore and the water became shallower, the tarpons reluctantly gave up on us and turned back into the inky depths to continue their nocturnal feeding. We emerged roughly where we had set out 45 minutes earlier, the outline of our pickup truck visible up on the beach — always a relief after a night dive. There was a cool night breeze blowing across the water, and with it came the smell of jet fuel from the nearby airport. We all surfaced exclaiming and laughing, buzzing with adrenaline after our night of hunting with the tarpons. I glanced at the still-luminous dial of my Panerai and reset its bezel to 12. It was close to 9:00pm and time for a well-deserved beer.