Balanced diaphragm with manometer OR unbalanced piston with manometer and depthmeter

[alfred1]

Hello,

I've found two offers on about same-quality brands, each with its pro and cons.

They're at the same price, so I am having some difficulties weighting the pros to see which one I should choose.

Set 1 has a balanced diaphragm 1st stage + 2nd stage + octopus + pressure gauge
Set 2 has a compensated piston 1st stage + 2nd stage + octopus + pressure gauge + analog depth gauge

Which one would be a wise choice?
I'd be using a wrist computer anyway, however I don't know how to weight the added analog depth meter.

It probably is a matter of taste, however given the knowledgeable and experienced people posting here, I'd like to read any comment.

Thank you!

 

[tbone1004]

depends on the specific first and second stages. Most divers on this site prefer "naked" SPG's, as they technically aren't manometers *most people just use manometer to refer to any pressure gauge, but they are technically only the liquid filled tubes, think barometer type*. SPG's are most all bourdon tubes which are bent by the pressure similar to a spring.

You mention using a wrist computer, and in that case you won't bother with the analog depth gauge anyway so no point in having it. Combine that with the fact that I prefer diaphragms and on a general consensus I'd leave to set 1, but much of it will depend on the specific brand and models of each, as well as the price *to make sure it is actually a good deal*.

 

[alfred1]

I see, thanks for your reply.

You're right, I was referring to tank content pressure gauge and they're indeed built as you've specified.
That "double" thing about depth gauge is probably a thing of mine. I know wrist computers are really secure but I sometimes get that odd low battery or malfunction in my head which an analog would be (still in my head) less likely to have.

Hoping to clear some things up:

Set 1 is Mares MR12s Rover
Set 2 is Seac P-Synchro

Some online specs I'd find:
Mares 12s
First stage: Balanced diaphragm design
HP Ports: 2 HP 7/16 UNF ports
LP Ports: 4 LP 3/8 UNF ports

Seac P-SYNCHRO.
The simple efficiency of the piston.
High reliability, safety, sturdiness, durability, and simplicity make P-Synchro the ideal regulator for the intense activities of schools and diving centres.
Tests conducted by RINA, the Italian certification board, confirmed excellent performance with an extremely low respiratory exertion.
First stage materials: shiny chrome-plated brass
• Second stage materials: ultralight technopolymers
• HP outlets: 1 . LP outlets: 4

Thank you

 

[tbone1004]

personally I wouldn't consider either, but that's just me. Mares wins on having the extra HP port which can help with hose routing, but the reality is neither of those first stages offers an elegant hose routing scenario.

https://www.divegearexpress.com/regulators/sowpkg.shtml
Look at the pictures and videos on there

http://www.unterwasserwelt.de/pics/mares_12_instinct12s_03g.jpg
compared to that, which is a less offensive picture of what those regulator styles can look like for divers. It's not even a comparison. I'm not sure what country you're in or what options you have of purchasing, but I'd look at some other first stage designs first, especially the swivel turret style with 5th port. It will be a bit more expensive, but it will work a lot better in streamlining.

 

[alfred1]

I understand. If safety and functionality is not an issue, I would personally rather look goofy than hand out extra money, though that's just me being a tightwad and putting perspective only on safety or else "who cares"

I'm in Italy so there are plenty of brands to choose from.

 

[tbone1004]

the safety and functionality come into play with the goofy hose routing as well, especially if you have any sort of penetration in your future. Also consider the value of a sealed diaphragm particularly if you plan on diving in salt water primarily, the ease of cleaning is quite a bit better with a sealed diaphragm. If you're trying to support local business, the Seac DX100/200 ICE are sealed, Mares and Scubapro both have sealed options as well. Unfortunately both Seac and Mares are following the typical Italian flair type marketing schemes with lots of gimicks, so you have to read through most of that.

If you plan on going into technical diving, consider options that you will be able to easily service yourself as that is very important to most technical divers. Apeks XTX50/DST is the gold standard, check ebay to see if you can find them locally, much better long term investment. Scubapro MK17 or MK25 with the S600 or G250/260 second stages would be a good decision as well.

 

[ams511]

It is not a matter of looking goofy but more of a matter of safety and comfort. In the second pick tbone posted you can see the hoses can easily get snagged on something underwater. Also people with weird hose routing tend to have more issues with hose pulling than those that don't

You can be a tightwad if you want BUT one of the easiest ways to waste money in scuba is purchase a "good deal" on substandard equipment. If you like Mares and Seac both make first stages with different hose routing.

 

[alfred1]

I now see your points more clearly. I admit that I didn't think about this at all since I didn't consider cave or technical diving, there was only recreational diving in my head.

I take that all the 1st stages with a 90° bend on DIN attachment would work to streamline hoses, so the Mares Abyss 22 would apply too, right?
https://www.mares.com/common/__/products/416134_1.7e980210.jpg

While these "standard" barrel 1st stages are those which leave hoses hanging around:
https://www.mares.com/common/__/products/416209.1269675b.jpg

Is there anything else I am missing about the risks of having hoses not streamlined, other than risking to snag them?
That's not to undervalue your suggestion, just curiosity.

Since there's just 80 EUR (about 90 USD) in difference between
Mares MR12s Rover and
Mares Abyss 22

I think I should be wise enough to spend more now and be safer in the long run as well as squeeze more years out of the gear.


Thank you again

 

[ams511]

Whether you want to technical dive or not really isn't the issue. In my opinion even a sport diver can benefit from some of the ideas developed by technical divers. Besides reducing snags, streamlined hoses may reduce drag and hose pulling.

Regulators last a long time, there are still people diving double-hose regulators that are 50+ years old. So as long as you don't go broke it pays to purchase a good quality set in the beginning that will keep up with all your diving needs. That is why Tbone made the recommendations that he did. Before deciding on a first stage you should decide how you want to configure your hoses. Do you want to do it in a regular rec style or like a modified tech style like in this video.

 

[tbone1004]

what AMS said, whether you are technical diving or not, there is a better way to do it, you see many more recreational divers going with bp/w systems over jackets because they are just better. They may never get into a cave or inside of a wreck, but the harness/wing system is superior, it was the original system *albeit without the wing portion*, and continues to be the best system out there. The "streamlined OW" configuration that Dive Rite has been pushing for the last couple of years is nothing new, many of us were using it for our singles rigs for the better part of the last decade for two reasons. 1 it was better, and 2. it made the transition from doubles quite a bit easier. The fifth port only required one blanking plug to be swapped with the primary regulator.