TIMES CHANGE. Divers now enter the water with little hand torches that are far brighter than could have been imagined even five years ago, and with burntimes that equal a weeks leisure night-diving.
Manufacturers of those lamps that were connected to a big battery by an umbilical cable have had to rethink their marketing strategy. There just arent enough people doing deep cave penetrations.
However, it seems that a lot of divers like to ape these adventurous heroes, and they will still need a battery-pack behind which to tuck the long hoses of their Hogarthian-rigged primary regulators. Perhaps the battery-packs required can simply be made smaller.
Halcyon, with its strong connection to a training agency that evolved from Florida cave-diving, has always supplied kit that satisfies those who believe it represents the best way to dive, and Global Underwater Explorers (GUE) has evidently been tied up
with the company in a novel marketing strategy.
Knowing that this market is attracting divers in numbers that would make the underwater cave systems of the world look like Piccadilly Circus Underground station during the rush-hour if they all actually used their lamps for this sort of diving, other manufacturers are getting in on the act. Its no surprise that they are mainly American.
Hollis Industries was spawned to meet this demand. Bob Hollis is the grand old man of the US scuba industry, with manufacturing companies such as Oceanic, Aeris, Pelagic and Romi under his familys wing. It is one of his sons who heads up the technical diving section that bears his esteemed family name.
Today, I find myself in possession of two very similar looking technical diving lights from each of these companies. Like anyone who might be in the market for such a thing, I wonder how they measure up.

Needless to say, both products are made to the highest manufacturing standards, with lamp-heads beautifully machined in anodised aluminium that is both durable and corrosion-resistant.
Both come with Goodman-style handles that allow the user free use of the hand that is holding it. Both are permanently adjustable, using a cross-headed screwdriver.
At last Halcyon has bitten the bullet and come up with an LED lamp-head, the EOS LED Primary Light. It should be a lot more robust than the HID heads that prove so popular until the moment the owner tonks his on the deck, and the bulb and ballast needs replacing.
LEDs are incredibly tough, with an anticipated life cycle of 20,000 hours. Halcyon also claims that this lamp is brighter than its 10W HID.
The EOS uses three LEDs mounted together, with a total consumption of 12W. Full output is claimed to equal 600 lumens, which equates to 1450 Lux at 3m.
Built-in thermal protection auto-switches the lamp to a low intensity to protect the LED array from over-heating if it is turned on while out of the water. Otherwise, it has two output settings, full- and half-power.
The Hollis LED16 takes a slightly different direction in that it uses a single, ultra-high-power 16W LED that pushes out more than 1000 lumens, and allows the designer to use
a deep reflector to give a tight, piercing beam of light. This LED is said to enjoy similar longevity to its less well-endowed relatives.
The head is narrower and deeper than that of the multi-array EOS. The manufacturer says that it is especially good at signalling. I would think you could attract the attention of a passing Nimrod pilot, it appears so bright.
The type of beam you prefer is down to personal choice. The Halcyon EOS is rated
to 90m, which should be enough for most of us. The Hollis LED16 is rated to more than 150m.

Power Supplies
Both lamps have battery-canisters machined from Delrin, with rather nice switches covered in a waterproof plastic and well-guarded against unintentional operation. Outwardly, they are uncannily similar.
Both canisters have similar arrangements of jubilee clips and webbing, for attachment to a waistbelt or a tank via a camband.
The Halcyon lamp is supplied with an E/O wet connector, so that it can be fired up from
a battery-pack that might be also powering something else, such as a heated undervest.
This means that the user needs to choose the most appropriate of three ni-mh power supplies.
We had the smallest, the 4.5amp version with a canister thats around 30cm tall and 6.5cm in diameter. It gives a five-hour burntime with the EOS on full power, or double that at half power.
The Hollis canister is a little squatter at 22cm tall, and a few millimetres fatter. It
uses a lithium-ion battery that gives a four-hour burntime.
Internet diving forums are heaving with discussion about the relative merits of
ni-mh v lithium-ion. Lets leave it at that!

The Hollis LED16 gives a tight beam of warm light. We were very surprised to discover in our side-by-side comparison that, despite all the paper specifications, the beam of the Halcyon EOS was not only wider but also whiter, and about 50% brighter.
In fact I would suggest that this lamp has the most satisfying output of any Halcyon lamp yet.
This was over a distance of around 2.5m, and measuring the output of the beams on the pool wall with a submersible light meter.
That said, unless you find yourself diving alongside an EOS owner, you would not be unhappy with the output of the LED16.

Both manufacturers expect you to open the battery-canister to connect their intelligent
fast-chargers. Both use cam-catches, commonly used on expensive underwater camera housings. These bear down onto big O-rings to keep the water out.
You simply plug them into any supply between 110V and 240V at 50-60 cycles. An indicator light on the charger tells you when the times up. The big fan-cooled Halcyon charger is stupefyingly quick.
Both lights allow you to connect up the head the wrong way, so that they are safe
for transport. The connections for the heads are both superbly constructed.

The race for customers for these lamps will be neck and neck. It will take more than a pundit like me to say which one will win by a nose.
The horse-racing analogy is a valid one. At the prices of these lamps, youll need to bet on a winner to be able to afford one!


LIGHT OUTPUT600 lumens1000 lumens
DRY WEIGHT1.8kg1.8kg
BUOYANCYminus 0.8kgminus 0.9kg
DIVER GUIDEwidth=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%