Dive Computers (Suunto vs Oceanic)

[scubadada]

After further research the NDL limits appear to vary greatly at shallower depths, but are within a few minutes at deeper depths (80 or more, which is what I tend to dive). I suppose at this point it is just a matter of preference and price as my LDS won't rent computers.

It's not just the 1st dive NDLs you can get out of the owner's manuals, it's how the computer handles repetetive dives. You can't get this information out of the manuals.

---------- Post added June 7th, 2013 at 01:42 PM ----------

Nv,

I have been diving Suuntos for about 20 years now - starting with the "Suunto Solution Alpha" - and for a while now I have been diving a Suunto D9 (Suunto RGBM) and a Hollis DG03 (which is more or less an Oceanic VT3, Bühlman ZH-L16c). Surprise, surprise: even on Deco dives with complex profiles, both show NDL-times and later deco-times within 2 minutes of each other. So unless you really want to push the limits using a tekkie-computer, I would go with the one you simply like better. I don't see any responsible Suunto or Oceanic users walking around with the bends.

In my opinion:
Changing the batteries is easier with the Hollis (Oceanic) plus the batteries are more easily available, and changing gases underwater is more intuitive.
Changing the Suuntos batteries is a lot more finicky (but that's the D9) but they last much longer, display of NDL/Deco-info is clearer and overall usage is more intuitive.

The Hollis DG03 uses the Pelagic Z+ (Buhlman ZHL-16C based) algorithm. The Oceanic VT3 uses the Pelagic DSAT algorithm. The former is more conservative and would likely match the Suunto algorithm more closely. The Oceanic VT4.1 and many of Oceanic's other newer computers, including my Geo2, run both algorithms and you can choose which you'd like to use. There are also conservative factors to further increase the flexibility and allow you to closely match many of the available algorithms.

Changing batteries for my Geo2 is simple, it's more difficult for my VT3. I got 28 months and 240 dives from my 1st VT3 battery and got 18 months and 170 dives off my 1st Geo2 battery. I changed them electively shortly after the 1st low battery warning came on.

 

[Dive_Gypsy]

I have owned the Uwatec Tec 2G, the Oceanic VT3, and the Atom 2.0. I currently own the Atom 3.0 and OC1 from the Oceanic line. I also own a Suunto D9tx (my first Suunto) and have dove the Zoop and Vyper. For deeper, longer dives I am very happy to have the Shearwater Petrel as my primary computer. I will share some details (trying to keep it non-technical) of my experience with the Oceanics and the Suunto.
Oceanic
- user-friendly controls, easy to read display, reliable, standard algorithm will allow you longer bottom time on successive dives, customer-service is bar none.
- be very careful changing the battery. If using Macdive you sometimes have to play with the USB cable in order to connect to the Mac and be able to download dives.
- if using an air integrated transmitter, distance from transmitter could cause you to lose air pressure display.
Suunto
- feature rich, robust, excellent compass (D9tx), quality materials, complete package.
- dive deep or close to a non-decompression limit and even after a 45 minute surface interval you will find yourself with very little comparative no-deco time on the 2nd dive. I have observed a 21 minute difference between a Suunto and an Oceanic.
- have not had to use their customer service yet (knock on titanium).
- When in compass mode you lose non decompression limit (NDL) display or decompression time remaining. Their in-house DM4 software on the Mac will lock up the application to the point of frustration.

I appreciate them both and cannot give you an opinion either way other than to say that if you are doing multiple dives or a live-aboard the Oceanic will be more bottom time friendly. Once you have narrowed it down to a particular model, I am happy to give you more input. If in the US, Oceanic service centers can be found almost everywhere. If diving in Egypt or Europe you will have more luck finding a Suunto service center.

 

[Lorenzoid]

Dive_Gypsy, this may be getting off topic, but what do you perceive as the advantages of the Shearwater over, say, Oceanic and Suunto, for "deeper, longer dives"? I sometimes see people on SB recommend the Shearwater for rec-only diving, and other than it having a good user interface, I wonder what the advantages might be. My thinking has been that if I hope to do deeper, longer dives in the future, the safest way would be for me to learn deco procedures. As I see it, just getting a more tolerant/liberal computer isn't really addressing the root problem and is more of a work-around that comes at some increased (perhaps slight but nevertheless increased) safety risk. Is my thinking off-base?

 

[Dive_Gypsy]

@Lorenzoid:
The Shearwater Petrel is a dive computer designed primarily with technical diving in mind. It supports decompression mixed-gas open circuit and closed circuit diving. So this is piece of kit that will allow you much room to 'grow and go' as far as you want in rec/tec diving. The algorithm used is the ZHL-16C (with gradient factors) by default although you can also buy an upgrade to use VPM B. Essentially what gradient factors do is allow you to adjust the conservatism or liberalism of your decompression based on the particular dive on the particular day you are about to do. Cold? not feeling 100%? After training are you doing a dive that is extending your limits? Adjust your gradient factors to suit the conditions. For an excellent article explaining GF look here: Gradient Factors. So now you have more control over your non-decompression limits and the conservatism of your planned decompression. You are absolutely correct in that no computer at present will ever do your thinking for you or accurately predict what level of nitrogen saturation your tissues have at a given moment in time..so owning a Petrel 'forces' you to learn about decompression modeling. I would not say it is more 'tolerant' computer I would say that it offers more flexibility based on your input. The manual which is an education in itself is available here: http://www.shearwater.com/wp-content/uploads/2013/02/PetrelManual_1_1_0.pdf. As and if you decide to move towards technical/decompression diving the Petrel allows you to add and delete gases on the fly so say if you were diving with multiple gases and for whatever reason failed to retrieve a 'staged gas' for decompression the Petrel will re-calculate your decompression on the fly once you have 'let it know' you have a lost gas. You can define up to 5 different gases.

You have flexibility over battery choice, swapping batteries is easy for someone like myself that has fumble fingers when it comes to most mechanical operations. The display is easy to read, very informative and you can also customize it to show you the information you want. It uses Bluetooth to download/upload information which means no futzing around with cables. Firmware updates are easy. It is wrist mounted, compact and rugged. Ask for one word to describe the Petrel and I will say it again: flexible. It can do any kind of dive you want to do (with the proper training).

To be fair I will say what it does not have: a compass and air integration. Most in the technical community avoid wireless transmitters on their 1st stages so air integration is virtually a non-issue.

It sells for $950.00 which is not cheap but also half the price of top of the line recreational computers. If I had to choose just one this would be it but get the training first. Even if you don't fall head over heels for technical diving the training alone will make you so much more of a confident, skilled, knowledgeable and safe diver. I can recommend some very good instructors and I personally hope to be teaching PADI technical courses in the near future. Happy to answer any other questions you may have and to add that I would be remiss in saying that if you do get in to decompression diving 1 Petrel will not be enough..you are going to need a backup computer as well.

Happy & Safe Diving!

 

[Lorenzoid]

Thanks, Dive_Gypsy. I think I've got a decent handle on the rudiments of gradient factors from the book Deco for Divers (Mark Powell). And I've read a little about Shearwater's computers and their flexibility. (I suppose other tec computers are similarly flexible, but Shearwater has a lot of fans on SB, it seems). So that's basically the main advantage as you see it: flexibility. Okay, thanks.