[efattah]

Last weekend we repeated the no-suit deep dive.

The water had cooled down, 14C on the surface, still 6C at depth.

This time there was a huge current so I was afraid to go all the way to the bottom at 80m. I turned at 73.6m and finished the dive in a more speedy 2'31". I had lots of air left and was very clear headed.

Some important changes from last weekend:
- Did the sinking phase with one arm extended, since with no suit, extending just one arm is very easy (while pinching the nose with the other hand)
- Ascended faster and with arms extended (again, without the suit, there is ZERO resistance to extending the arms, and the cold water in the armpits further cools the core body, which reduces metabolism)

Once again I got into the water with 1 minute before my 2 minute countdown. I didn't hyperventilate as much (to reduce the risk of samba), but I really paid the penalty for that, because with the increased CO2, the CO2 narcosis/anxiety effect was stronger on the ascent, even compared to the 80m dive. If anyone wants to read about CO2 narcosis, you should read the study done at Duke University. The bottom line is that CO2 has its own narcosis. If you inhale 100% O2 at sea level, and exercise in apnea, you will eventually get strong CO2 narcosis and eventually black-out from CO2 toxicity, even with 0% nitrogen in your lungs.

The descent time was 1'31", the ascent time was 1'00".

Someone asked about chest flexibility. Even with no warmups, I avoid squeeze in the following ways:
- Recreational dives all year round with an occasional negative dive
- Yoga breathing exercises including nauli kriya, year-round
- Extremely slow descent on my dives
- Extremely relaxed chest & body on the descent, due to mouthfill equalizing technique (no chest effort or strain from doing deep frenzels or valsalvas)
- No suit in cold water causes extremely fast blood shift; this would require MANY negative or FRC dives with a suit, in order to simulate

The competition is next weekend. I was thinking of announcing 75m or 77m. Any requests?