Practice and Timing

As for time,. I haven't had much lately so my blogs are few and far between... still diving "too" frequently, editing the footage, and creating new episodes for my cable TV show to have much time to blog. That bwill change as "winter" (in SoCal?) approaches.

Had an interesting day yesterday. It was a three tank dive on my fave, Scuba Luv's King Neptune. I've been doing a lot of deep (> 130 ft) diving to film the critters there in anticipation of a new episode of my TV show on "Deep" Ecology.

First two dives were to 180 feet for a total dive time each of 50 min. I issentially follow a transect line straight down from the anchor line to max depth, move about 15 ft up current (to get out of the resuspended silt cloud) and swim an up transect to the shallows.

Both dives were uneventful with no problems. Plenty to film given my limited bottom times (I only stay below 100 ft for 10-15 min), and quite different life at the two dive sites.

I planned to only go to 140 ft on my third dive and as I approached that max depth, I looked up to see a torpedo (Pacific electric) ray about 7 ft above me! I started filming it and it stayed with me for quite a long time. I kept an eye on my deco obligation as I filmed and as I neared 30 min, I started heading back to the shallows making several deep stops along the way.

I've gotten pretty good at judging my air consumption and managing my gas (straight air). I figured I would complete the full 31 min deco obligation using my primary tank. I always keep the pony mounted, but have never had to use it for deco.

I completed the obligatory deco as my SPG hit 600 psi. I practiced gas management for years when I was doing non-deco dives so I'd be ready for these type dives. Since I'd been on two very deep dives, I decided to do an extra 10 min of deco using my pony which gave me a good safety margin (all other obligatory deco stops were similar over-extended for safety).

The take home message? The years I spent practicing gas management during my non-deco dives really has paid off now that I do frequent deco dives. I used to set goals for my diving... for example, one dive to 100 ft for 45 min and a second one with the "same" profile from the second half of my HP120 tank. I'd have to adjust my depths through the two dives to make sure I had enough gas to complete my goal and surface with ~500 psi. It has given me a good knowledge base on my air consumption rates at different depths... pretty handy skill now!

5:12 PM - 9/28/2006 - post comment