This SAC rate thing.....could it be over rated?
When I first started diving, I was diligent about writing down numbers, exact numbers, starting tank PSI and ending PSI and bottom time and hang time and then dividing and multiplying and dividing again and then factoring in depth and gear and currents and water temps and then taking into consideration the phase of the moon, the icecream flavor of the month and the price of tea in China.... I would have an exacting SAC rate which I would double check against the online SAC calculator. I still have a multifunction Scientific Texas Instrument calculator in the bottom of my dive bag because of this.
What I found was:
1. I didnt have a bad SAC rate
2. I didnt know any other girl divers to compare my rate to
3. All the guy divers I knew had higher SAC rates
4. Everyone knew girls have better SAC rates than guys and
5. No one cared what my SAC rate was.
I also found that for the diving I was doing.....my SAC rate really didn’t matter in terms of gas management. I was running out of NDL before gas, even with nitrox.
My dive planning was always around run times and NDL and my gas always more than sufficient. Life was good. I went to the bottom, poked the fish, saw the sights, came up and had gas to spare.
I logged my bottom time, my depths and kept up on my weighting, which I still struggle with. Noted what there was to see, which wrecks were best for the lobsters and where the mussels were. But starting and ending PSI slowly gave way to the variety of fish to poke and what was scattered about in the way of debris to put the ship whole again in my minds eye and unusual events. Which conditions of depth, temperature and visibility put the boogeyman at the end of the line and how I dealt with it. Boat ladders, crew and dive buddies. All details.
I always check my starting pressure when I set up my gear, I always check my PSI as I dive, and use it as a gauge of when to stop sightseeing and start back, and I always get back onboard with gas to spare. But I stopped tracking the actual numbers at some point.
Now, I am being called on the carpet for my laxness. I am looking towards doubles and when discussing it with my dive buddy I have been given a list of considerations to take into account as I move forward. My biggest considerations are weight and maneuverability. If I cant carry it, I do not think I should be diving it. So the big question comes down to size. HP 100’s, LP 85’s, or even 74’s are in the running. Hmmmmmm, how do I decide. Apparently, according to “someone”, gas management answers this question.
So, I consider what I want to dive, where I want to dive and how I want to dive it. I then consider how often that will happen.
For the immediate time being I will be diving the recreational limits and upsetting my computer with occasional 10-15 minute deco obligations. Soon...heliox and some of the deeper and more interesting things just outside my door. After that and some experience....advanced deco and more bottom time and a little deeper.....I just am not limited ever.......how do you plan for what you just cannot imagine.
There are so many things out there to see. More than enough under 100 ft to keep me busy the rest of my life, I am sure. But the history draws me. And the stories. And so many of them are right there, right out my back door, and just a little bit deeper than I should go right now. The big boy wrecks out by the canyon and the mudhole.... where the artifacts are found, the scallops are laying about, the big fish swim. The stories of the S-5 and the Texas Towers. I want to dive a submarine, the towers, a wreck with portholes still intact, see where the big fish swim and the octopus live, watch sea lions and dolphins play, see a wreck that hasn’t been dragged by the Coast Guard and pounded by the weather, do a dredging dive and a numbers run and discover something totally new. The things to see and the fish to poke........more than I can imagine....how do you finalize a list like this?
So what is the next question? How big a tank do you need? How do I find this out? Using math and my SAC rate. Jeesh!!!
Does my SAC rate really matter? Get out my trusty calculator and a pencil, then run the dives on V-planner and then figure that if I see a really big shark, or a whale, or I am dragging 100 scallops stuffed in my goody bag and my pockets that my SAC rate is out the window anyway. And in an emergency situation I think my condition would be more than “my heart is all aflutter” ...... so.....
Does my SAC rate really matter or should I figure my tank size on the average for where I want to dive and a little measure of added safety for me and my air hogging buddy. It troubles him that I dont track my air consumption. He cant see how I can choose my tanks without it. I cant see how I can limit myself with all there is out there.
I have no problem admitting...there is so much I dont know, have not seen, cannot imagine...and I promise to keep better track of my air consumption.....but in the end, does my SAC rate define the future of my diving or do I plan my dive around the moment. This wreck..... in these conditions...... using this set of tanks and equipment.....I can visit this long. I think doing the math is a guy thing.