Please explain more as to how LOW O2 will allow the line to sink? I am a swift water rescue tech and know that anything in a HIGH o2 water will not be as bouyant. Many drownings occur due to this reason around low head dams and such. How would an otherwise floating line then sink with less dissolved oxygen in the water? If it works, great, I just don't see the facts to back it so please don't think I'm stirring anything up, just need to have the theory explained to me.