I’m new and need some help!

[jonhall]

just strap to my wrist, giant stride in and the computer will then do its stuff

If you exceed the NDL, you will need to do a decompression stop. Your computer will show you that,

Agree with @WilliamT and @boulderjohn. Should be able to strap on and go (I have the i550c), but get to know it and continuously refresh yourself with symbols. Watch the NDL time - hopefully your first dives won't take you there, but best to understand what the computer is telling you to do just in case.

 

[Pippam]

Thank you for all the comments, really helpful

 

[TMHeimer]

I have the simple Mares Puck computer and know how to see my remaining bottom time and depth. Also use the old dive watch and analog depth gauge as backup (old habits...). Those manuals are meant for a different generation than mine, but I at least know the most imprtany stuff. You make sure you have a good battery, jump in the water and it does it's thing.

 

[scubadada]

Hi @Pippam

I have a slightly different take.

You did not say if you are nitrox certified. It you are diving air, you will leave the set gas on air (p21). If you are diving nitrox, you will set it each time your mix changes.

There are a number of things you will want to set once unless you change your mind about the setting. This includes the alarms (pp 22-24) and the utilities (pp24-28). Time is self-explanatory (p28). The mode will be dive rather than gauge or free diving (p29).

If you have questions about the alarm and utilities settings, you can ask additional questions in this thread. I, and others, tend to have biases regarding how we would set them.

Once these are done, the computer is ready to dive. You will want to be familiar with the screens you might see or want to see during the dive and learn to pay attention to your computer and your SPG.

Best of luck with your diving. Let us know how your trip goes and how you like your computer.

 

[Angelo Farina]

If you are diving with nitrox, you will need to know how to program those settings.

Or just leave your computers set to air and consider Nitrox just as an additional precaution against decompression sickness (the "bends").
The drawback will be a shorter dive, but safer.
This is what I usually do.
Only thing to remember is that breathing enriched air the max safe depth is smaller, depending on the oxygen percentage in the mixture. But this max depth is still larger than 30 meters, which is the depth you surely do not want to exceed.
So, apart the slightly shorter dive time, there is no drawback keeping the computer set to air when using Nitrox.
And if you use small size tanks (10-12 liters) your diving time will be limited by the pressure gauge, not by the computer.

 

[inquis]

apart the slightly shorter dive time, there is no drawback keeping the computer set to air when using Nitrox.

Actually, the drawback is the safety margin then varies with the selected EAN. I would rather dial in an acceptable safety margin and always have it by not lying to my computer.

 

[Angelo Farina]

Actually, the drawback is the safety margin then varies with the selected EAN. I would rather dial in an acceptable safety margin and always have it by not lying to my computer.

Although this seems a wise choice, it happens that the diver makes an error setting the computer.
It happened to me to dive with a couple of guys who did mistakenly leave their computers set to Nitrox-32. We were on air and already on the edge of NDL (25 minutes at 30 meters) and these two were refusing to ascend, as their computers were far from NDL. I had to be very harsh with them for forcing them to end the dive.
It could well end in two bent divers...
That experience was convincing me that it is better not to mess with the settings of the computer...

 

[inquis]

Much like turning on your air, one can develop a routine for setting the gas in a computer.

 

[FishWatcher747]

Congradulations on starting your diving journey.

Do you have the wristwatch band for the I300c or are you putting it in a console next to your SPG? I bring this up because I started at the beginner level with the i300c in a console. I dove for 2 years like this and thought it was fine.

Then I got a used backup i300c on ebay with the wristband and wore it like a watch. Wow, what an improved way to wear your computer. It is way better for monitoring your depth. Also time, NDL, max depth. But the big benefit is being aware of your depth at all times.

Ever been in a down current next to a wall? Well you become aware of it way faster with the computer on your wrist.

For all the lurkers to this thread that still have a computer on a console you should look into getting the wristband for your computer.

For the i300c this is a strap one can buy. I'm sure there are others for different computers. Check the specifications.

 

[NYCrecdiver]

Or just leave your computers set to air and consider Nitrox just as an additional precaution against decompression sickness (the "bends").
The drawback will be a shorter dive, but safer.
This is what I usually do.
Only thing to remember is that breathing enriched air the max safe depth is smaller, depending on the oxygen percentage in the mixture. But this max depth is still larger than 30 meters, which is the depth you surely do not want to exceed.
So, apart the slightly shorter dive time, there is no drawback keeping the computer set to air when using Nitrox.
And if you use small size tanks (10-12 liters) your diving time will be limited by the pressure gauge, not by the computer.

I heard this before but for the life of me cannot understand why anyone would dive nitrox and set computer to air. Set your computer for the gas you breath so it gives you the right information. You want a safety margin? Just stay within x minutes of the (correct) NDL shown. Or set your conservative settings accordingly. Imagine you're encountering something really interesting at depth. You KNOW you can stay longer cause you're on nitrox. But now because of your decision to put in the wrong gas, you can't stay down longer w/o your computer telling you to do a deco stop that in actuality you don't have to do. It's just messed up and you've created problems that aren't there.