I too have concerns of rate of accent, however I'd rather be at the surface than on the bottom if my breathing stopped. The reason for my consideration of this device is because I'm a solo diver most of the time. I do have someone on the surface in a boat that could assist me if needed in an emergency.
There has been a lot of bashing of the product, but, I'll try analyze this seriously.
Like okiedown, I am a solo diver as well. In my solo and technical diving training I have learned to solve almost any problem underwater, EXCEPT losing consciousness or capability to react (due to medical conditions, ox toc or bad gas). If you lose consciousness whilst solo diving, there is a big likelihood of you dropping your regulator and sooner or later breathing water. Perhaps that would be a last chance awakening call.
In the lost consciousness/capability situation, even an imperfect ride to the surface will be less risky than 100% sure drowning.
An additional benefit is to lessen the trauma caused to next-of-kin if the body is lost in the depths of sea since it might take a year or longer before all the legal and funeral proceedings can be handled (depending on country of course).
However, the product has several shortcomings:
1) the newer version monitors lack of breathing for 40 seconds until it sounds its alarm. Well maybe the alarm might "awaken" the unconscious solo diver?? But only after a further 20 seconds does the device start ascending you. For a false alarm situation the 20 seconds is much better than 7 seconds. But, for an actual emergency situation you would already have lost a total of a minute. Remember that brain damage is likely after 5 minutes of not breathing.
2) the ascent rate should definitely be controlled. But why isn't there any autoinflating/deflating/autoadjusting BCDs on the market? Perhaps autodeflating/adjusting is just too risky for technology i.e. manufacturers´ liabilities.
3) the device is much larger than other inflators on the market. Based on the pictures on their web site, it would seem far more cumbersome to reach the deflate button and to deflate the BCD especially in situations where you need to react fast. This shortcoming alone is sufficient for me not to purchase the product.
4) I wonder how the device should be cleaned and maintained (unless this meant only for once-a-year holiday divers who do not care)
5) There are obviously more failure points than with a regular inflator. Most of my dives are in cold waters (4 degrees Centrigrade or colder) and there is constantly the risk of the inflator freezing. With a more complex design the risk is greater.
6) not suited for multitank diving because the device is not able to continue breathing monitoring.
7) would add risk in overhead environments without any benefits.
Based on the above, I would not purchase this particular product eventhough as a solo diver I feel I have a need for something like this. For a solo diver, a full-face-mask would be a better option, but, that is another story.
