Scubapro 1st stages...clearing up the mess

[Moogyboy]

all

Okay, so what is the consensus about Scubapro's first stages? I'd really like to have SP in my frontline of choices in a new reg, but so many people here keep blasting their 1st stages for cold water, especially the Mk25. Granted, I'm not usually doing drysuit-class diving--most of my diving is between 60 and 80 degrees--but fairly occasionally I will be in a fullsuit in a quarry, or less often up in the Great Lakes where bottom temps are down to the 40s. So how cold is COLD where SP's regs are concerned?

On a broader note, here's what my perception of what the general opinion is:

Mk2--an old standby, classic unbalanced piston, some say it's great in cold water, some say I'll grow out of it quick.
Mk16--balanced diaphragm, good compromise, but needs an enviro seal kit, or something.
Mk25--lots of parts, definitely freezes and freeflows more than it should in cold water. People seem to hate it but use it a lot anyway.

I suppose I'd like to consider a Mk16/R190 or R380 combination as my general purpose reg. I'd also look into an Aqualung Titan or Titan XL, or perhaps a Cressi Airtech so any opinions about these ones in comparison to the two SPs would be nice.

I dunno...I know this subject has been battered into the ground sixteen times over, but I figure I'd rehash it to reflect my own personal circumstances.

cheers

Billy S.

 

[archman]

My MK2+/R190 combo has done me just fine for many years, though I'd like a reason to upgrade to something lighter and more compact. I'll still keep the older regs around, as they're near indestructible. But the coldest waters I commonly dive are 68 degrees.

The Mk16 I don't think has a swivel, which drives a lot of folks nuts.

The R380 is an R190 shrunk down into a significantly more compact housing. I'm eyeballing that model myself.

You didn't mention Apeks regulators, which I believe are designed by renegade ScubaPro engineers. They're well regarded on this board.

 

[MookieMoose]

I spent the last 3 years diving almoast exclusively the Grate Lakes from the Canadian side of the border - Georgian Bay has bottom temps aroung 45 F in August. I use a Mk 25 and never had any problems with it freezing up. I can't speak for anyone elses experience, but I believe that it performs just fine in cold water, provided you don't over-tax it (ie try to inflate your drysuit, inflate your BC, and breathe heavilly in deep, cold water all at the same time). It's a solid reg, but is not environmentally sealed, so ti you get the flow rate through the first stage too high in really cold wter it can freeze.

The Mk 16 is a sealed diaphragm first stage (my wife uses one of these) so it shouldn't freeze. The down side to it is the single HP port. It's cold water performance is great, but not a good choice if you need.want more than 1 HP port. Hope this helps.

Cam

all

Okay, so what is the consensus about Scubapro's first stages? I'd really like to have SP in my frontline of choices in a new reg, but so many people here keep blasting their 1st stages for cold water, especially the Mk25. Granted, I'm not usually doing drysuit-class diving--most of my diving is between 60 and 80 degrees--but fairly occasionally I will be in a fullsuit in a quarry, or less often up in the Great Lakes where bottom temps are down to the 40s. So how cold is COLD where SP's regs are concerned?

On a broader note, here's what my perception of what the general opinion is:

Mk2--an old standby, classic unbalanced piston, some say it's great in cold water, some say I'll grow out of it quick.
Mk16--balanced diaphragm, good compromise, but needs an enviro seal kit, or something.
Mk25--lots of parts, definitely freezes and freeflows more than it should in cold water. People seem to hate it but use it a lot anyway.

I suppose I'd like to consider a Mk16/R190 or R380 combination as my general purpose reg. I'd also look into an Aqualung Titan or Titan XL, or perhaps a Cressi Airtech so any opinions about these ones in comparison to the two SPs would be nice.

I dunno...I know this subject has been battered into the ground sixteen times over, but I figure I'd rehash it to reflect my own personal circumstances.

cheers

Billy S.

 

[scubadoguk]

You didn't mention Apeks regulators, which I believe are designed by renegade ScubaPro engineers. They're well regarded on this board.

I think the apex make was originally British design, the store I work at has mk16 and g250 hp on special I was thinking about one myself.
Cressi we have them in rental and are still there!! they work but for some reason don't seem to be very good at anything,
all the rental scubapro 1st stages are mk2.

 

[greyface]

I think the apex make was originally British design, the store I work at has mk16 and g250 hp on special I was thinking about one myself.
Cressi we have them in rental and are still there!! they work but for some reason don't seem to be very good at anything,
all the rental scubapro 1st stages are mk2.

I dive the MK16 / R380 with local water temps only down to low 50's, and love it. My pony reg is a MK 2+ / R180 and works like a champ, as well.

 

[msandler]

I put dozens of ice dives and too many to count 40deg. dives on my MK15 environmentally sealed with silicone and a "boot". Never a problem. Couple with a G250 (not hp). It is an outstanding breather forcefully delivering more air than you would ever need with two divers!

I don't know about the newer stuff though a MK25 is definitely on the radar. I wish they still had non-HP versions of the G250 - I like the metal.

 

[rescuediver009]

The Mk16 does not necessarily require a seal. It is just the desing of the reg that is more impervious to cold. If you are always going to be above the forties, I would say that you are fine. SP is known for their MK25 and I would say that this reg is fine for the temps. Especailly above 50 degrees. I wouldn't be too afraid. It is by no means an ice reg, but will suit you well. Tobermory, as mentioned on the canadian side is one of the coldest places around and they do fine there most of the season. I realize that Apeks wasn't mentioned also, but don't want to steer you from your desire. Stick with it. G250 or S600 will spoil you rotten.

 

[DA Aquamaster]

A Mk 2 is a bulletproof design and adequate in terms of performance at recreational depths. It is also a reliable performer and excellent choice for ice diving. And they work great on deco bottles.

The Mk 16 offers good performance (approx 170 scfm) and should be adequate for all but the most extreme depths, and then you should be using a helium mix which pretty much negates any flow rate concerns. The Mk 16 is also very relaible in cold water/ice diving. The ambient chamber is not sealed, but it is very open and allows a great deal of heat tranfer, is largely isolated from the business end of the reg, and utilizes a teflon coated spring. I suppose you could freeze one up theoretically, but you would have to abuse it in the extreme to make it happen.

The MK 25 is an exceptional performer (approx 300 scfm) but has a history of freezing up in water colder than about 45 degrees if it is not handled properly. You do not want to over breathe a MK 25 or inflate the drysuit and BC and inhale all at the same time in very cold water. Low pressure tanks also work better as they reduce the adibatic cooling load on the reg. Personally, I dove all last season in water with bottom temps from 39-45 degrees with a Mk 25 and 2475 psi tanks and had no problems at all in 130 dives.

The SPEC booted Mk 10, Mk 15 and early Mk 20's were extremely reliable in cold water but the design was bypassed in preference to the current TIS system which does not have as much margin for error as a properly packed and maintained SPEC boot. Using silicone in the ambient chamber also creates the potential for cross contamination on christolubed regs intended for service with nitrox. Some care was needed anyway to ensure the ambient chamber was properly packed and this was not always done by techs who did not like cleaning out the old silicone or packing the new silicone in the ambient chamber

The Mk 20 has a higher parts count than the MK 10, but I would not say the parts count is excessive by any means. Compared to the Mk 10, it has 2 bushings to support the HP o-ring and an extra spring (to hold the bushings in place). The Mk 25 does nothing more than add an adjustment in the seat retainer for external IP adjustment. A half dozen parts overall over the very simple Mk 10, does not consititute an excessive parts count.

 

[matt_unique]

Mk25--lots of parts, definitely freezes and freeflows more than it should in cold water. People seem to hate it but use it a lot anyway. QUOTE]

I would clarify to say people use it because it is without question one of the best, and possibly the very best, deep breathing regulator available. It does have the freeze problem as a draw back. My brand new reg free flowed in 46 degree water (118' at the time) after an unusually large breath. I immediately had adjustments made and it has not free flowed since and I have tested it in colder temps. I have friends that ice dive with them and never have free flows. I'll have more of my own experience to offer with this reg after this winter. (The adjustments have been addressed at length in other threads so I will not list those here).

--Matt

 

[billtodive]

I am an out of shape inexperienced diver. I dove my MK25/s550 at <45 degrees for over 30 minutes of constant depth changes ( lots of heavy breathing and bc inflation), and practiced air sharing ( buddy on R190 second). This was before I was told of the 25's tendancy to freeze up. I don't think I'll concern myself, but I keep my buddy close in cold water/ difficult dives anyway. I have been told you can de-tune the 25 enough to minimize the ability to freeze up; more experienced people here can maybe clue me in on that.