Question ScubaPro MK17 (not EVO) 1st Stage, C300/R295 second stages and UWATEC gauges - opinion.

[SubSurfaceSierra]

Hello all,

I have been given the above set up and obviously will get it serviced but just wandered what the opinion was on it.

Diving will be mostly colder water, and quite new to diving.

I am just wandering how decent it is or whether I should look to develop / upgrade it perhaps to the MK19 Evo (prefer membrane) and G series second stage.

 

[Mobulai]

The mk17 (all 3 gens) is a champ in cold water, keeper for sure
Unless you feel a need for the swivel turret of the mk19; the xtra weight aint worth it (I use 19s for sidemount, but it’s a heavy mother)
——

C300 is a cool design, some EU cold water divers prefer downstream over balanced 2nds, and it (along with face lifted c350) is a good candidate for that

I love the Gs; the g260 is just a work of beauty; I love balanced 2nds in general

it’s up to you if Ou want a blanced 2nd or not (more on that around in threads and/or ask and will try my best to answer)

On a Balanced 1st stage… theoretically not so much to gain unless we’re talking serious wob/depth/flowrates/gas density
—-

R295.. that’s the one with (user) unadjustable Venturi, not a fan, but I hear it performs more than alright…
Never dove it, can’t really tell
I’d personally change it because of the Venturi thing, or have it tuned perfectly for stable Venturi + have it stiff (but then ise it only in a „light“ warm rec setting)

Edit:
As a whole rig, it’s a good combo and serve you (when serviced and in tune) well till you start doing really demanding dives

 

[BoltSnap]

The first stage is excellent; there are no issues with it. I'd want a balanced second stage. I don't use unbalanced second stages myself, not even for alternate seconds.

 

[rhwestfall]

@rsingler

 

[rsingler]

Great setup!
Can't beat the Mk17. The EVO improvements are incremental, and of no consequence to the recreational diver. Parts will be available for decades. Sealed for cold water diving is a significant advantage, and the added cold water hardiness of the EVO and EVO2 might be significant if you are literally talking 40°F or less, when you say cold water. Otherwise, meh.

Second stages:
Cold water freezups on the second stage side are a function of technique and heat conductivity.
Despite my absolute respect for @BoltSnap , the one advantage an unbalanced second stage has over a balanced reg is simplicity. Fewer moving parts that might be affected by a fleck of ice in the mechanism. No tiny balance chamber. They can be tuned to breathe just as smoothly as a balanced reg, albeit requiring more frequent tuning.

Both the C300 and R295 are plastic. That's good for shedding ice crystals and poorer for heat conductivity.
The R295 is an old standby that any good tech can service. Great breather and easy to tune. Again, lots of parts around.
The C300 doesn't have a spring in the airflow path, and has a round lever which won't get jammed with ice. But its less common design means that finding a tech who can take care of it is a bit more of a challenge. The one thing to be aware of is that the C300 can deliver huge flow! It's a real favorite of mine. So if you're in warm water and have to kick for your life in current, it's a fantastic reg. But if you're in cold water, make sure to dial the Venturi lever to Min, or it can get away from you and freeflow to an immediate freeze with mishandling.

 

[SubSurfaceSierra]

Thanks everybody the advice and insight is very useful.

In terms of temperature dives it will mostly be UK based cold weather March to November so I imagine the water temp to be 0-10 degrees. I think a balance second stage would be a good idea and so seem to be choosing between the G260 or the S620Ti. I gather both are balanced, diaphragm, sealed but the G series is heavier? But any thoughts on either one and exuding which would be great. I have to say that the first stage regulator will continue to be the MK17 +/- evo MK19 Evo as prefer the membrane element in the cold gritty water.

On a similar thought stream does anyone have any opinion on braided hoses? Any good? Worth it? Good in cold?

Thanks all

 

[Mobulai]

Wow that’s cold, you’re far braver than I

If you’re set on a balanced 2nd
My vote would be the g260
@BoltSnap would vote the s620, I think
I can’t say if one has an advantage over the other in cold water diving..
their barrels are brass and titanium respectively; no clue how that impacts thermal exchange

I like that the g260 has a seat saver and a micro adjustment inside the knob (not on the 620)
Edit: I’m wrong, the 620 has a micro adjustment

The dry weight of the g260 is more indeed, and it’s bigger; but a bigger chamber means more buoyancy, so in water it makes no big difference (if you’re thinking of jaw fatigue)

 

[BoltSnap]

Wow that’s cold, you’re far braver than I

If you’re set on a balanced 2nd
My vote would be the g260
@BoltSnap would vote the s620, I think
I can’t say if one has an advantage over the other in cold water diving..
their barrels are brass and titanium respectively; no clue how that impacts thermal exchange

I like that the g260 has a seat saver and a micro adjustment inside the knob (not on the 620)
Edit: I’m wrong, the 620 has a micro adjustment

The dry weight of the g260 is more indeed, and it’s bigger; but a bigger chamber means more buoyancy, so in water it makes no big difference (if you’re thinking of jaw fatigue)

I say spoil yourself, the S620Ti for primary and g260 for alternate

That's what I am ordering with the MK17 EVO2 I'm getting.

As for the braided hose, I don't use them anymore. They tend to float which is annoying especially with the long hose. For short hose, it is somewhat ok.

 

[BoltSnap]

0-10 degrees

I think that it maybe a little warmer, 2 degrees warmer