When I've been searching and viewing videos in my
Freediving Video Collection, I did not see any real action of a counterballast system, but there is a video of a test of such system on the website of Performance Freediving. In the video collection, it is listed in the
PFI section under the name of "
Cayman 2005 DIVER DOWN: Safety Setup" (in the bottom half of that section).
Otherwise, I saw countless videos of CW/FI turns at the bottom platforms and saw that divers sometimes seem to unnicely hurt at the bottom, banging their head or arms on the platform. It happens because they are sinking rather fast and while keeping the streamline position they do not see the platform coming.
I already wondered if it is not too dangerous - I could even imagine that it could knock out someone, and definitely the shock may cause loss of concentration or even air, if not the loss of conscience. I imagine that if you activate the counterweight and the platform starts lifting with high speed, in the moment it reaches the freediver, it can seriously hurt him too. Personally I always doubted the security of such setup and also wondered what the practical results were. So far I did not see, or did not read about any cases of real use, so cannot argument, but am little bit sceptical.
I'd tell that at least the bottom platform (or the part that will lift, if the platform stays in place) should be made from some really soft material. Maybe a huge plastic or rubber ball filled with water, or partially with lead? Such ball shaped platform would be also more hydrodynamic and would rise much faster than a flat platform. I find the often used metallic platforms quite dangerous, and especially if they are used to be lifted with a counterweight and then tow the victim to the surface.
Another security aspect I was often thinking of, is the question whether safety divers, photographers and other folk in water is well trained and instructed to stay clear from the corridor where the counterweight sinks. In case of an accident it would be fatal if someone was under it.
