Mk25 Scubapro

[Belce]

I came here looking for advice on regulators and when I said I was going to get a Mk25 1st for diving before this spring 2009 I was told that would be a poor choice due to local water temps and free flows trouble. The advice here was contray to all my real world diving experience with people using this 1st stage and I am happy to continue to report they remain wrong.


WRONG

Yep that is right, outside of extreme cold like diving under the ice on a fresh water lake or the ice at antartica the Mk25 1st stage is great in "cold water" and tested with 4300 psi at 2C without trouble. That is right, it is the required performance level for the regulator, your cold water reg might not make that.

Anyone that says a Mk25 Scubapro 1st stage has trouble with cold water below 50 F is incorrect. They don't know what they are talking about and my experience and dive log says different.

People on this forum claiming expert status Protray the Mk25 1st stage as a poor choice and they are completely wrong. And when I say this I do so with such previous orgainsations linked to as the United States Navy indicating that not only is the Mk25 good cold, they approve it.

[Packhorse]

I have 2 Mk25's ( and 2 Mk20's) and love them. I never dive in cold water (10deg C is the lowest) BUT I still respect others opinions and if enough people say there is a problem with MK25's in cold water ( add to that the design which isnt really optimal for cold water) I wouldd tend to think there is something in it.

Perhaps you just have very good cold water diving techniques and the MK25 is less forgiving for other people, who knows?

All I know if I was looking for a cold water reg I probably wouldnt go with the MK25. But then im not and I am very happy with my '25s and '20s not to mention all my other SP regs.

[tstormdiver]

Yes the MK25 is a great regulator. I have 5 of them. They do have some tendency to free flow; I've had it happen once in about 200 deep dives at the local quarry, at 95ft in 42 degree water, but with careful management & it is usually a non- issue. It is a great & very easy breathing regulator.

[awap]

I once drove through a stop sign without even slowing down and did not have an accident. Does that mean that folks who claim that ignoring a stop sign can cause accidents are incorrect?

[tgsmith]

When I first started diving the Mk25 AF was recommended to me by both a shop in Vermont and a shop in New Hampshire, in addition to a friend of mine who was a decompression diver(he had his in 28* without a problem). So I bought one.

Now that I'm doing my own decompression diving I haven't had a problem with any of my Mk25's free-flowing in cold-water. I've done decompression diving in as cold as 40* water, and shorter no-stop dives in as cold as 36* water with no free-flowing issues.

Does it have a higher propensity to free-flow compared to a sealed diaphragm reg? Sure, I'll buy that. Does that make it unsafe for diving in cold waters like so many cyber divers claim? Not from my personal experience......

[tgsmith]

I once drove through a stop sign without even slowing down and did not have an accident. Does that mean that folks who claim that ignoring a stop sign can cause accidents are incorrect?

What experience do you personally have with a Mk25 free-flowing in cold water?

Must get REAL cold down there in Texas

[awap]

What experience do you personally have with a Mk25 free-flowing in cold water?

Must get REAL cold down there in Texas

My objection was the faulty logic. By design, a high flow rate flow through piston reg with the ambient chamber open to the environment is subject to encounter freeze problems occasionally, especially wityh poor techniques. Just because a large number of divers do not encounter such problems does not change the fact that the design is not the best for cold water use.

My Mk20 saw 49 degrees once here in central TX. It performed just fine but my wetsuit left a lot to be desired. I doubt I'll be doing that again.

[scubafanatic]

....not here to 'dis' Scubapro MK25's...but anyone who's followed the reg section of this board over a long enough time will see LOTS of reports/observations about the MK25 'sucking' as a cold-water reg...and if you're gonna dive SP in 'cold' go with something like the MK17 1st-stage instead...the MK17 is an excellent/modern 1st-stage...and unless you need something like a MK25 for some special house routing needs (i.e. doubles) why fool with the MK25 when the MK17 is just as good, and meant for 'cold' ?

[halocline]

why fool with the MK25 when the MK17 is just as good, and meant for 'cold' ?

One reason is that the MK25 is built like a tank and has proven to be ultra reliable and stable over years of use.

Regarding the cold water use, I'm happy to say that I have no experience with freezing temps, but it does seem clear that the 2nd stage has a lot to do with the MK25's cold water performance based on repeated reports.

If we get another ice age anytime soon and I find myself diving in frigid water down here in TX, I'd use a MK5 or MK10 packed with Christolube. What I don't really understand is why cold water fans with MK25s could not likewise pack the ambient chamber.

[scubafanatic]

.....it is my understanding that some of the older SP piston regs did offer a SPEC kit similiar to the little rubber band/Christolube combo Atomic uses.....but it is my understanding SP abandoned that approach a long time ago (for reasons unknown to me) so for a while now all their piston regs go 'naked' without even the SPEC kit option available....maybe SP thinks cold water divers need to just use a diaphragm 1st stage and be done with it?