I've just purchased a Suunto Vyper, which is the same as the Gekko (pretty much). What type of questions did you have? How to get it into dive mode? The computer has only three buttons, a SMART or MODE button, and two other buttons (scroll up and scroll down - these also have other functions depending on when they are used during a dive or which mode your currently in). So for example, to change from air to nitrox I would do this:
1) Press the SMART or MODE button (to either turn it on and go directly to time, or hold it a few seconds to reset it and go into dive mode if it's off).
Now the unit is in Dive mode. So if I jump in the water, it'll start working as I start going to depth.
2) Press the SMART or MODE button (since the computer is now on and ready to go) to take us to the main menu options. From there Press TIME (or SCROLL DOWN) to see SET.
3) From there press the SMART or MODE button again to select SET. From there, press the TIME button (or down arrow) to scroll down the list of options you can set. For us, let's keep pressing until we see SETPREF.
4) Now press SMART or MODE again to select that level of options. And again, use the PLAN and TIME to select what your wanting to set. Let's try SETPREF. After you see it, press the SMART or MODE button to select the set of preferences options you can set.
5) From here, press either the PLAN or TIME button (remember these buttons also are scroll up and down - they have more than one "shared" function depending on where you are), until you see MODEL. Now, press SMART or MODE button to select the RGBM model you want to use.
6) From there you can select AIR, GUAGE or NITROX. To get back to the main menu (Dive mode), just hold in the SMART or MODE button for around two seconds. Keep pressing TIME (scroll down) until you see NITROX, then press SMART or MODE. Remember to set the correct O2 levels in the gas mix your using among other things if your using NITROX. The computer should be set to AIR by default.
I hope that gets you started. It's kinda hard to explain, but it's like a tree branch ... the first SMART or MODE press lets you select the limb you want, then as you go down the limb, more limbs appear. Just select you limb you want and press the SMART or MODE (do you see where it's now shows select just to the left in the window?), to start with those sub-options. Then once you select the sub-option (or catagory if you will) use the SMART or MODE button to put you on that path.
It seems a diffcult way to do it, but remember they're really only using 3 buttons to do many different things.
I hope this helps some.
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Mike.