I have used the Black Diamond Icon LED headlamp over a dozen times at night and it works well.
The Icon has two LED light configurations. The high output configuration is comprised of a single 3 watt Luxeon LED. The 3 watt LED puts out a surprising amount of light. BD doesn't state a lumen output, but comparable 3 watt Luxeon lights output 60-70 lumens.
Regardless of the specific lumen output, the 3 watt spotlight bulb is incredibly bright. There are three brightness settings. I use the highest setting to scout my beach launch and landing site.
I often launch from a beach on a river which sees a good deal of tugboat/barge traffic. The barges often wash up large rocks and other debris on the shore. And, of course, I always have to check for broken bottles or other litter left by visitors to the area.
I use the high setting when landing at the end of my trip. Even though I may have scouted the area well just a few hours ago, a passing barge or littering beer drinker sometimes causes my launch site to be impractical. I approach the beach parallel to the shore, in about a foot of water. I turn the 3 watt light on high and scan the riverbed an beach. The light easily penetrates the murky water in my area.
I use the 3 watt light for two other purposes: Illuminating substructure (logs, stumps or debris beneath the water surface) and to "wake up" an inattentive power boater. I never flash the 3 watt light directly at a speeding, dangerous power boat operator-I want to jolt him into awareness, not blind him. I tilt my head back and aim the big light up into the sky while moving my head to port and starboard. This works very well.
The Icon also has four lower power LEDs. These are arrayed with two LEDs on each side of the center 3 watt bulb. The four LEDs provide excellent wide field illumination. The low power LEDs also have brightness settings and a strobe mode. The strobe fires on the high setting and is very effective.
The switch design is, however, quite flawed. A single large rubber membrane switch controls both the 3 watt and 4 low power components. The Icon is supposed to "remember" which you used last and energize that. My unit doesn't work that way. I rarely need to use the 3 watt bulb when underway, but sometimes the click that should energize the low power (my last use) turns on the 3 watt bulb-at high power. This ruins my night vision for several minutes.
Princeton Tec has a similar headlamp, the Apex Pro. The Apex Pro has separate, dedicated switches for the low and high power components. Better still, the A-Pro switches have either four bumps or one bump corresponding to the light component activated - a valuable tactile reinforcement in case one forgets which switch operated which component.
I purchased the Icon as I had an immediate need for a high power headlamp after some dangerous power boat encounters-my local outfitter didn't carry the Apex Pro.
The Icon can use alkaline, lithium, or rechargeable batteries. I have not been using rechargeables. Other manufacturers, such as Pelican and Princeton Tec clearly state, on their websites or via marketing information, that their lights have a reduced 3 watt output when used with rechargeable batteries. As I need all the light I can carry and immediately activate when some fool power boater is approaching at high speed in the dark, I do not take a chance on the Icon having a diminished output.
I have attempted to determine the technical details, to no avail. My outfitter called BD's field rep for the area and I spoke with him in detail, but it was obvious that he just wanted to "blow me off" and get back to what he was originally doing before my call. I asked him specifically about the possible reduced 3 watt output and he responded, "Uh yeah, I think the Icon would probably be less powerful then."
"Uh. Yeah. I think. Probably." Those words are unacceptable. I clearly and politely asked that he forward my request for qualified technical information to BD's engineering dept. I supplied my telephone # and email address. Of course, no one has contacted me in the month since... I also left a message on BD's website politely asking the same-again, no reply. I am quite disappointed with BD because of this.
BD rates the Icon as "submersible." I am doubtful. The battery compartment does not use an O ring, and the charger port (the Icon has a proprietary battery pack as an option) has a rubber cover, but it fits poorly. The Apex Pro, and other submersible rated headlamps, uses an O ring between the battery compartment halves.
The four LEDs are placed such that some light spills downward and into my face. Even on low power, this is irritating. I have colored the bottom of the lens with a black permanent marker in an attempt to remedy this. My effort is somewhat effective. BD obviously should have extended a light blocking lip 1/8" below the LEDs to prevent light spillage.
The Icon has no red LEDs. I find this to be a particularly poor design for an expensive ($60) light intended for extreme use in wet or wilderness conditions at night. To be fair, the Apex Pro does not have any red, green, or blue output either. I will likely add one or two Princeton Tec "Pilot" puck lights to the headband for night use. The PT Pilot comes in multiple LED colors (green or blue may actually be better for night vision than red). The additional weight is of little concern.
It seems impossible to find the headlamp I need. Multiple mfrs produce lights similar to the Icon or Apex Pro. None produces a combination low/high output waterproof headlamp with a colored LED output for reading charts or checking my deck gear at night. I have become accustomed to creating or modifying much of my gear, so I will continue combining the best features and components of various products to suit my needs.
The Icon is a functional headlamp. The high power setting should fulfill any serious illumination need you have. The low-power setting provides good wide area coverage and long battery life. The functional shortcomings of the switch and poor customer services due to BDs corporate philosophy are, however, disappointing and unacceptable. I recommend this light only if you have an immediate need and cannot locate the Apex Pro.