Oh, how I wish the dive computers manufacturers would read this..... are you getting this Mr. Suunto R&D man???
wrist vs. console
- wrist, so that it is easy and convenient to read on ascent. Also, I would hate to have a big, clumpsy, over-sized console hanging off me.
air integration (console)
- No thanks...this would mean I had to have my computer in a console. Not worth it. Though for a newbie diver, having an idea of remaining air time can be useful...and the side-effect of that information is that they can develop a quicker understanding between the effects of depth, breathing rate and their air consumption.
air integration (wrist / hoseless)
- I never bothered with the tranmitter option for my Suunto D9. I never missed it. Though for a newbie diver, having an idea of remaining air time can be useful...and the side-effect of that information is that they can develop a quicker understanding between the effects of depth, breathing rate and their air consumption.
integrated compass (wrist)
- the digital compass in my D9 is ok for a quick reminder of direction, but is not as easy to use a a proper compass when it comes to 'real' navigating. That said, it does mean I can carry one less piece of clutter on a regular basis, as my proper compass has become an 'optional' item, dependant on my planned dive - rather than a core item I carried every time 'just in case'.
ascent alarm
- I don't use/set an audible alarm on mine because I tend to track my ascent on the ascent speed indicator anyway. The ascent display is invaluable, but the alarm would only benefit muppets to stupid to use their computer to monitor their ascent speed.
other alarms
- I don't set any depth/time alarms, because I prefer to be disciplined in my situational awareness during the dive. I do like a PPO2 alarm for nitrox diving though...given the immediate dangers of exceeding MODs. Useful as a back-up for novice divers though.
graphical display
- My D9 has a nice matrix design and I feel it is a big improvement over the LCD displays in my Vyper and Apeks Quantum.
data download to PC w/software
- Not essential by any means. I like this function mostly because I use it as a training aid (the graphic dive profile and tissue pressure graphs) when teaching. Back in the days when I used to log dives... it suited my lazy streak to plug my computer in, rather than fill out a paper logbook.
memory
- As long as it tracks my current nitrogen, I don't care. Back in the days when I used to log dives... a bigger memory suited my lazy streak as I ad to plug my computer in less often.
gauge mode
- essential for technical dives, where I use laptop generated tables and need 2 timing devices/depth gauges to run the dives with.
number display size
- I liked my 'big' Apeks Quantum for diving in the UK (low viz). Here in Asia, the smaller, more detailed, D9 screen is just fine.
number of buttons
- I loved the user interface on my Apeks Quantum...very good menu system and intuiative navigation with 3 buttons. I found the Vyper to be a real hassle. The new Liquivision X1 has no buttons at all (just tap sensors on the sides) and my friends who have them absolutely rave about it.
good looks for everyday watch
- as a full-time dive instructor this is an appealing function for me...it means my computer is always there and never left behind!
algorithm / tissue groups
- I appreciate the RGBM model...and like being credited for Deep Stops with my D9. The best options for me would be algorythms that accurately reflected the V-Planner or GAP programmes...for easy and accurate predictive dive planning on my laptop.
battery type and user-replaceable or not
- User replaceable!!!! My Apeks Quantum is great...a regular, easy-to-obtain watch battery and you only need a coin to open it. I dread my D9 battery going...I will have to send the computer away for a very costly battery replacement! One really good thing I have seen is the rechargeable Liquivision X1... that really takes the hassle away completely...as long as you have a power socket available before diving!
nitrox
- Esssential. With PPO2 alarm and, preferably, customizable PPO2 settings.
other fancy gas settings
- I do accelerated decompression so 2 gasses (Quantum) is nice. 3 gasses (D9) is great. Trimix capable and 4+ decos is best.
freediving mode
- a good feature, if it wasn't for the fact that most computers then lock you out of dive mode for 48 hours!
backlight
- A strong, clear backlight is essential for me...when night, low viz or penetration diving. The Liquivision X1 has the most amazingly bright display of any computer on the market...I want one of those just for that feature alone!
temperature gauge
- never really 'needed' this, but my students/customers offen ask what the water temp is.
stopwatch
- my D9 has a stopwatch, but you cannot access it in dive mode. I wish you could, because as a dive instructor, there are many skills that we are required to time! Even a divetime display in seconds (not whole minutes) would be a useful advantage.
Safety Stop
- All my dive computers provide a display counting down the safety stop. However, only the Quantum provides the count-down in Seconds. I really like the accuracy of that... it helps me plan/prepare my next actions better.
Average Depth
- Useful for calculating general air consumption (SAC) rates.
Time
- My D9 allows me to toggle the sub-display onto real world time (not bottom time). This is useful for me as an instructor...when I am trying to keep my lessons/schedule on track...it can also be beneficial if diving in areas where tide/current changes.