Blackcrusader
Contributor
While the resulting SAC rate is impressive, I don’t think it would withstand exploratory dives where one covers hundreds and hundreds of meters.
I've done 90 minute dives where I covered 1.5km from boat and ended the dive with a shore exit at the dive center. The dive was actually more of a swim back to the dive center. With good technique and a steady pace Even doing exploratory dives covering hundreds of meters my SAC rate is still less than 10l min at a nice steady pace. Same when I swim against currents. Managing your technique do you don't over exert and get tired out is important. I was on a dive into a current with a diver with two AL 80's on sidemount. He had less air at the end of the dive than I did as he struggled with the current. He should have taken some rest stops along the way but decided not to and really was too tired. I would duck behind a large fan, or some outcrops and take rests while this other diver would do 10 fin kicks and only be another 2 meters gained and I easily caught up. He did not make the next dive 90 minutes later as he was too worn out and he was half my age. Do you think every dive is done in optimal conditions?
The OP was asking about efficiency.... being efficient applies to diving with a current or into a current. Good techniques and not over exerting when into currents will also give divers better dive times. I often see divers who really over exert themselves when swimming into a current. They try to go too fast and tire themselves out and get into heavy breathing even to the point they nearly hyperventilate. That's just bad technique. Using less motion means requiring less air.
Here I am chasing down a whale shark at near full pace to get some photo's you can see I pass another diver as well. A few hundred meters covered.. But I still keep a decent use of air. Still completed a 90 minute dive after this chase at 32m depth.