Rock Bottom Spreadsheet

[limeyx]

And further to that, you should be able to "field calc" this stuff sitting on a boat in 1m waves for any depth the day may give you as well, IN YOUR HEAD.

No pens, paper, calculators etc........all you need is one sheet out of the wetnotes that have the RB's of your common tanks (if you haven't comitted them to memory already). And be able to extrapoltae quite easily every piece of info you require to do a dive from there.

Once you're able to do that, you have arrived. It doesn't take 100th decimal place accuracy nor even 5 minutes of time. Imperial or Metric.

Regards

Exactly. Having said that, the spreadsheet method is great to start out with -- a paper version of it is what I was given to start with.

Carrying a slate with RB's written down seems to allow one to shut one's brain down a little too much for my liking. And carrying your buddy's RB means you either have a less experienced buddy or a non-trustworthy buddy -- which might mean you need to take other additional steps.

I calculated RB for tonight's dive in doubles in about 3 seconds -- took the RB I use in the same tanks but singles, divided by 2 and made sure it was still above 500psi.
easy.

 

[Scuba_Steve]

The reality of it is, you dive the same tanks over and over so you should have it to memory as I suggested.

It's for the one-off times you don't,(i'm thinking cuban russian steel tanks or some crazy tank I've never seen before) and since you have wet notes (not a slate) with you all the time (don't you?), it takes up half of one page to be looked at on the boat. That's not shutting your mind off, that's being prepared, and even to help the next guy if he's interested, which he isn't

People should learn how to do it without spreadsheets or calculators at all. It's just too simple to figure out the means with grade 6 math, in your head, on the fly. If it's not, you're going about it in the wrong way IMO, and it lacks real world application.

 

[Scuba_Steve]

Further to the above, I think people get off on the wrong foot in thinking they require decimal place accuracy, which they simply do not.

Using the sames tanks doubled up, as stated is brain-dead easy, and even then if you come out with less than 500psi you round up to 500psi. So much for any percieved accuracy you may have thought you needed, which again, you do not.

I challenge anyone to show me 3-4cf difference on their gauge. You can't.

I realize why/how people think this. For myself, it was because my TDI classes required XX number of hours of inclass work, so I had to endure reams of paper-work nonsense to calc gas consumption, 02 exposure blah blah blah for every depth and stop.

Well hey, I was damn accurate!

The reality of it is I couldn't duplicate it on a boat or without software/pen/calculator, and a half-hour to do it

Accurate? yes, ..........real world applicable? Hardly.

Required?.......No.

I'm a fan of easily duplicated events that you can do in the water if you had to. Yes I know this goes beyond RB's.......but it fits in here as it's all a part of gas management, and a part of getting you and your buddy back on the boat safely, and having a practical means of doing such.

Sure there's a benefit to knowing how to do this, and if you follow or can make a spreadsheet, you've accomplished it.

Now make it practical to the point you could get tossed a different size tank and not sweat bullets or be scrambling for the calculator!

Regards

 

[vondo]

Someone said my attachment was broken. I've also updated this for a metric. Here are the newest versions.