BigBlue CF600 Focusable Beam Dive Light – a Concept that Misses the Mark

BigBlue Dive Lights is an innovative company and we loved their bullet shaped Auto Flash Off (AFO) Focus lights. But the new CF600 focusable beam light made us wonder out loud, “did the designers of this light every take it diving?” In many ways the CF600 seems like a concept prototype or beta version of a dive light. The CF600 is the big brother version of the smaller focusable CF250.

What we liked

As a basic dive light the CF600 is a standard shaped dive light that feels good in the hand. If your needs are simple, set it on your favorite beam width and you have a light with a few stellar attributes. These include a stunningly bright, cool color temperature beam with good penetration on only 3 AA batteries. Yes, that is correct, only 3 AA batteries for that much light. You can and should use rechargeable batteries because you get about 2 dives before the lumens start fading. The insides are protected from flooding by a double o-ring seal. The easy and distinct magnetic switch means you have a simple, one-handed operation with nothing penetrating the aluminum shell to leak.

Where it disappoints

The highly touted focus feature is accessed by twisting front bezel to change the beam angle from 8 to 28 degrees. This sounds like a great and innovative feature BUT… as you descend in the water the bezel becomes harder to turn. At around 50 fsw an attempt to focus can cause you to counter rotate and loosen the battery compartment access end; and possibly flood the light. At around 80 fsw the focusing bezel is just too difficult to bother turning. This is the main reason I suspected that no one on the design or testing team ever took this light diving.

There are two other issues that tarnish the thrill of the focus feature. The CF200 is basically a flashlight with the projector lenses on one end. If you remember playing with old slide projectors, you may recall focusing the lens (with no slide in the chamber) and seeing a clear image of the bulb filament projected on to the screen. This is what happens with the CF200. On the tightest (brightest) focus (8 degrees), you project four, nearly distinct  square images of the LED modules (It is a one LED light with four modules.). It is oddly disconcerting and the gray cross image makes the sharpest focus not practical. The wider, 28 degrees beam is not that useful either. Most divers who tried the light or whom we talked with expressed the conclusion that a focusable beam, or at least this one, did not add much value. This light without the focus feature, would be lighter, less expensive and could be a winner.

We also noticed that while the aluminum shell seems rugged on first glance, it is actually very soft and showed significant signs of wear after only a few dives. The tempered optical glass projector lens also gives the impression that this light is more fragile than most. When I asked friends if they wanted to try it, some said they were afraid they would break it.

Unlike most primary dive lights, the CF600 has no variable power. It is either on or off high power. That means you are burning the batteries as fast as possible through out the dive.


Overall it is amazing to have a 600 lumen (reported) light that puts out a cool penetrating beam on only three economical AA batteries. We also wish other light manufacturers would follow BigBlue’s practice of using non-penetration, easy on/off magnetic switches. But we mostly wish that BigBlue would use their innovative skills in conjunction with thorough dive testing and feedback from the end user. We think BigBlue has other fine products and is a company to watch for new innovations. However, we cannot recommend paying the $399 MSRP for the CF600. We give the CF600 only 2.5 our 5 stars.

A better bet in dive lights and the subject of an upcoming ScubaGadget editors choice, 5 star review is the Sola Dive 1200.

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