Oceanic GT3 with which 2nd stage: SP5 or CDX5?

[gwells]

My wife went to our LDS and bought me a reg for christmas. Oceanic GT5 with SP5 2nd stage.

I went online and did some research to try to figure out whether I thought this was the right combo for me. I don't want to regret the purchase in 2 yrs and end up rebuying.

I'm a casual recreation diver, likely no more than twice a year. Open water certified, plan on nitrox and advanced certs. Don't plan on cold water diving, i like diving where it's warm enough to dive a 3mil or less (I dove belize in my rash guard), so I'm not worried about cold water performance.

Looking at the second stage options, the three big differences I saw between the CDX5 and the SP5 were balanced diaphragm vs unbalanced piston, environmental protection, and the extra high pressure port.

the primary functional differences as explained to me at the LDS (and from reading threads here) are balanced vs unbalanced and cold water functionality. cold water is not an issue for me. i've seen varying comments, however, about whether the balanced 2nd stage makes any real difference.

so, i'm asking here for advice. how much will balanced vs unbalanced potentially matter? are there other differences between these second stages that i haven't addressed? the extra high pressure port probably won't matter as much to me because i don't see myself switching to an AI computer any time soon (i have an oceanic veo 250 wrist mount).

am i missing anything else? should i be fine with the SP5 or are there enough differences with the CDX5 to warrant spending the extra $100 considering my diving plans?

Thanks in advance.

 

[MauiScubaSteve]

Alright; we need to touch up on nomenclature a little.

Here is a link to the Oceanic product page for the GT 3 second stage regulator, which normally comes paired with the CDX-5 first stage regulator;

Oceanic Worldwide - GT 3 Scuba Diving Regulator

The SP-5 first stage is normally paired with the Alpha 8 second stage;

Oceanic Worldwide - Alpha 8 Scuba Diving Regulator

The main use of the second HP port on most regs is so that reg techs in dive shops can assemble your reg set upside down from how is most logical to set it up.

Many shop techs even refuse to admit that the logo should be upright when mounted on a standing tank.

The SP-5 first stage is different in it's hose routing and I think it sticks the body of the first stage more into the back of your head while having more snagging issues with the top two hose routes.

Personally, I think in the long run the CDX-5 is a much better first stage, but don't bother with the DVT version if at all possible.

 

[v--Locke--v]

cdx5 is environmentally sealed sealed and has shown in testing to be one of the best breathing regs in last year's test... take it for what it is...

if you are diving in water colder than 50df I would take the cdx5, otherwise save your $$.

 

[fppf]

Yeah, you have your first stage second stage names messed up.

Anyway, your comparing a basic piston regulator with a more advanced diaphragm regulator.

If you can spend the money the diaphragm regulator is a much better choice. Diaphragm regulators are better sealed, have less moving seal surfaces, and will yield much better performance.

 

[gwells]

ok, i swapped the first/second stage nomenclature. doh.

reading through your post, your recommendation seems to be based on the way the hoses mount on the different regs (and that the CDX5 is a better reg, which makes sense because it's farther up their chain of first stages).

but beyond the way the hoses are set up, what's the real advantage for me? is it going to last longer? breathe better? i don't mind spending the extra money if i understand what it is i'm getting and that the value is there for me. but i want to understand why.

 

[fppf]

The CDX5 is sealed, which means less saltwater inside the body.
Less saltwater means less possible corrosion and longer life.

The CDX5 diaphragm design is a better design, breaths better.

Hose routing is a non issue for your self, don't worry about hose routing. That is the last thing you need to worry about.

 

[MauiScubaSteve]

Still not sure why hose routing isn't a big deal?

I would way chose a PX-3 over an SP-5 if there was a choice to get a PX-3. I am so glad my first new entry level reg purchase was a Scuba Pro MK-14, not because it was SP but because of hose routing. When I eventually took my cavern class my instructor complimented me on running it low profile and having hoses tucked properly. Doubt he would have let me use a Titan first stage or any other that routes like the SP-5.

I do not dive in cold water but I like my CDX-5 better than my FDX-10 DVT, and with the difference only $100 you will get way longer use out of the CDX-5 if you make any progress past occasional vacation OW cert diving.

In summary; yes it will last longer, it will breath better and the hose routing is better

 

[fppf]

From the OP's descriptions, hose routing is not an issue.
Does not sound like he will be doing cave.

Why do you like the CDX5 over the FDX10?
The only difference between the two is the body. Just about all the internal parts are the same.

 

[MauiScubaSteve]

Unfortunately the only FDX-10's available to me were DVT and the whistling is very anoying. I hope there is a way to remove the DVT when my annual service happens.

 

[MauiScubaSteve]

Open water certified, plan on nitrox and advanced certs.

you will get way longer use out of the CDX-5 if you make any progress past occasional vacation OW cert diving.

Does not sound like he will be doing cave.

I never said anything about cave.