Scubapro S555 versus S600

[scubajo007]

Hello Girls and Guys

I’m planning to upgrade my primary second stage regulator from Scubapro R295 to Scubapro S555 or alternatively S600.

The difference apart from the price is that the S600 has Diver Adjustable Inhalation Effort.

I dive primarily on holidays something like 10 to 30 dives a year in warm waters like the Philippines with maybe one or two dives a year in the North Sea in the summer time.
I limit my dive depth to an absolute maximum peak of 21m (70 ft) with a preferred depth range of 8 to 15m (25 to 50 ft) deeper dives will be quite far out in the future.

Now the question, would I be better off going for the S600 and would this improve the breathing or in my case is the Diver Adjustable Inhalation Effort facility just a nice to have thing.

Cheers,

Scubajo007

 

[Gombessa]

I don't typically mess with the adjustment knob on the S600, though I know some people who do. Either will be a great breathing reg, and as I understand it, the S555 is otherwise the exact same reg as the S600. In fact, I'm pretty sure one of my S600s is actually an S555 that's been serviced with S600 parts (you can have that adjustment knob installed) and an S600 faceplate/ring; you simply can't tell it apart from my other S600s.

 

[walke121]

I have 3 S600's and just purchased a A700 last week. The S600's are still my favorite regs. I strongly recommend them.

 

[redacted]

I like the adjustment knob. It allows me to tune the reg on the hot side and control any subsequent freeflow problems with the user adjustment. I also detune the rehg with the adjustment knob when using it as an octo and when diving in strong currents which may trigger freeflows.

 

[mk706]

I've been diving my S555 for the past year. I really wish it had the user adjustable inhalation effort adjustment knob. So much so that I've recently upgraded to a pair of Hollis 212s.

Within about the first 20 dives or so my regulator's cracking effort needed adjustment. My LDS, where the regulator was purchased, made the adjustment free of charge. Basically, what happened was that i noticed after about 16 dives or so the cracking effort increased substantially. I finished out the last dives on the vacation okay, but there was no way I'd have dived it again without adjustment.

 

[cbmech2]

Strongly concur with awap. Essentially the S555 is the S600 without the adjustment capabilities. For divers that know how this feature is supposed to work, it is an added flexibility and convenience. I myself would personally go for the S600.

 

[halocline]

Hello Girls and Guys

I’m planning to upgrade my primary second stage regulator from Scubapro R295 to Scubapro S555 or alternatively S600.

The difference apart from the price is that the S600 has Diver Adjustable Inhalation Effort.

I dive primarily on holidays something like 10 to 30 dives a year in warm waters like the Philippines with maybe one or two dives a year in the North Sea in the summer time.
I limit my dive depth to an absolute maximum peak of 21m (70 ft) with a preferred depth range of 8 to 15m (25 to 50 ft) deeper dives will be quite far out in the future.

Now the question, would I be better off going for the S600 and would this improve the breathing or in my case is the Diver Adjustable Inhalation Effort facility just a nice to have thing.

Cheers,

Scubajo007

What first stage are you using?

Some people like the adjustable inhalation, personally I wouldn't care much either way. You do realize that you're talking about very high performance 2nd stages in very easy environments, so I'm sure either one would work just fine. If you have an option to get the G250V instead, you might consider that. It has a metal air barrel which will probably help a little with drymouth, and it's definitely simpler and easier to work on.

 

[Interceptor121]

The adjustment will make no difference on your air consumption which is entirely controlled by the first stage.
I have a S555 which I use for work. It has a knob to be adjusted between pre-dive and dive position to prevent free flow in currents. That knob has a similar though less fine tuned functionality of the knob on the S600.
As an average recreational diver diving in warm water you would not be able to tell the difference between the S555 and the S600 while diving. I can tell you that because I tried that myself.
The S600 is a fine second stage which is superior to the S555 if you dive in cold waters and has more metallic parts than the S555 which is all plastic. In fact I choose the S555 because it is lighter to carry.
If you are not concerned about cost and you think of diving in cold water in thef ture buy the S600 without a doubt otherwise the S555 will be just fine.
Out of interest what first stage have you got? The first stage is far more important than the 2nd stage for your breathing comfort...

 

[redacted]

The adjustment will make no difference on your air consumption which is entirely controlled by the first stage.
I have a S555 which I use for work. It has a knob to be adjusted between pre-dive and dive position to prevent free flow in currents. That knob has a similar though less fine tuned functionality of the knob on the S600.
As an average recreational diver diving in warm water you would not be able to tell the difference between the S555 and the S600 while diving. I can tell you that because I tried that myself.
The S600 is a fine second stage which is superior to the S555 if you dive in cold waters and has more metallic parts than the S555 which is all plastic. In fact I choose the S555 because it is lighter to carry.
If you are not concerned about cost and you think of diving in cold water in thef ture buy the S600 without a doubt otherwise the S555 will be just fine.
Out of interest what first stage have you got? The first stage is far more important than the 2nd stage for your breathing comfort...

I'm not sure where to start.

The S600 and the S555 differ only in the user adjustment feature which is all plastic parts with a few o-rings. No difference in metal parts other than possible differences you may find based on when the regs were manufactured. I believe early versions of the S600 (and probably the S550) had metal barrels which were replaced by composite barrels in later production. That user adjustment feature directly effects cracking pressure and work of breathing.

The VIVA control on both those regulators effects the path gas takes as it travels through the 2nd stage. It has no effect on the initiation of a freeflow but may effect the severity of that freeflow once it starts. It has no effect on cracking pressure but can effect WOB.

A first stage can have some effect on overall regulator performance but the 2nd stage will have the greatest effect on breathing performance. Most 1st stages will make gas available to any 2nd stage in the correct pressure range and with sufficient flow rate to support comfortable breathing at recreational depths. It is not that the 1st stage does not matter, but the 2nd stage has the biggest effect.

An S555 can easily be set up to provide the same breathing performance as the S600. The difference is that as conditions change, the user can adjust the S600 to compensate for some of those changed conditions but the S555 may have somewhat lesser performance or experience a slight freeflow problem without going back to the shop tech for an adjustment.

 

[Interceptor121]

I agree that is he is only diving at 20 meters first stage is less important. But it does become important at 40 meters.

I also agree with the fact that you may need to fine tune the S555 if you change conditions, cold water or more particles in the water can make the regulator free flow.

What I do not like of the S600 is divers that play with the adjustment knob believing that they would use less air if they make it harder to breath but that is another story