[trux]

Yes, of course, Jose, but that's exactly what we are speaking here about. That's what is called bents or DCS. And if he staid so long down there and additionally had a belt that would shoot him up faster in the last meters, he would finish even worse than he did.

EDIT - addendum:
That's the principle of DCS - the longer you stay in depth, the more CO2 is dissolved in your blood, and the slower you have to go up. So if you use a BC device that allows you longer and/or deeper dives due to less energy consumed for the descent, buyoancy control, and the ascent, and additionally it allows you to ascent faster, then of course the risk of a decompression accident rises considerably.