There have been contradictory reports concerning the cause of the death of Australian Andrew Kilbride, 49 while undertaking technical dive training in the Batangas of the Philippines in May.
However, the one fact consistently reported is that the buoyancy cell of his diver's wing detached, causing an out-of-control ascent.
We suspect that it must have become detached at the lower edge, meaning that it was inverted above his head, making it impossible for him to dump air. We cannot understand how this could have happened if he was using back-mounted cylinders, since the wing is normally sandwiched between the diver (usually with a backplate) and his tanks.
That said, if the diver was using side-mounted tanks only, in conjunction with a side-mount rig, this could be possible if the bottom edge of the buoyancy cell was not attached securely, leaving the buoyancy cell free to "escape."
This happened to me while using an Italian-made Dive Systems side-mount rig in Egypt. The bottom part of the wing, secured with Velcro, became unattached, inverting above my head and making it impossible for me to reach it to dump air during an ascent.
Luckily, I was close to a reef wall and put my camera rig down while I recovered the situation. It had been dicey for a moment and could have been fatal had I been out in the blue. I took off the whole rig to re-attach it. I didn't use it again, and the product sank without trace (in the UK, at least) after I published my findings in Diver Magazine (UK).
If you use a sidemount rig, you must ensure that there is no way the bottom part of the buoyancy cell can become detached.
- John Bantin