SP MK25/S600 Freezeups

[sylvester]

I was at Mermet Springs this weekend. completing my Advanced course. All was going well and yesterday morning 1st dive was going to be the deep dive. I have been looking forward to it for months.

My Gear SP Mk25/S600 octo G250 BP&Wing. Primary Instructor SP MK25/S600 air II, DM SP MK25/S600 airII
All diving singles plan was drop to 100' look around swim to the 80' platform and assend from there. Simple.

Instructor was first on the platform I was 3d. DM followed the last advance student as soon as the DM was on the platform she had a free flow. and begain to assent. The primary instructor came to me and motioned for me to turn his tank off. I noticed the freeflow and handed him my octo a g250. I turned his tank on and off a few times over the next few minutes. he was swishing his s600 in the water trying to thaw it with no success. Then my S600 begain to Freeflow.

I turned his tank back on, controled my freeflow by crimping my hose like you do when drinking from a water hose, and showed him it was time to go, I now had problems also. He signaled me to assent and gave back my octo and was breathing his freeflow.

I was sipping from my freeflowing s600 controling the air with the kink when I remembered I had a good octo again. So I switched to it and was managing to choke off most of my freeflow during the assent. When I passes into the thermocline at about 20' my free flow stopped. I replaced my octo with my primary reg and hung out on a safety stop. At the stop I had 600psi left stayed there until I was at 200psi and surfaced.

Prior to the dive a plan had been talked, and another non-student diver identified, so in the event of equipment failure and the instructor or DMs have the problem the identified diver would ensure every one was off the platform and up. That plan was used and successful.

But looking back I wonder where was the problem? Was it 1st stage freezeup? If so, why did my g250 work flawlessly even when my s600 was freeflowing??

My reg ands well as the others that freeflowed are maintained properly.

What is the corrective action required to fix this?

Would a long hose on my primary prevent it?

Is the g250 better suited for the cold? Maybe I should be diving two of them.

Should I scarp my scubapro gear and find something I can put more faith into?

 

[MikeFerrara]

I don't use any SP regs and never will and don't know one from the other. However in the last couple of years we have run into lots of divers cussing their SP regs because of free flows in the winter.

 

[Big-t-2538]

How cold was the water?

Did the regs have an environmental kit?

Remember not all regs that come out of the box are suited for Cold water diving....that being said, I have never had a free-flow, but do know of one student who was taking his advanced class 2 years ago and had a free-flow with his SP reg.

 

[sylvester]

water at 100' was 38 deg F. I don know about the enviormental kit. I was under teh impression when I bought mine it was sealed to prevent these problems.

 

[Ber Rabbit]

I dive an MK10 with 2 G200 regs and have never experienced any cold water problems.
Ber

 

[Big-t-2538]

sylvester- Did you read the specs than came with the reg...or just take it on faith from the LDS where you got the reg that it would be good to damn near freezing temps???

Ber- I know you dive a SP reg, but if you remember the story of our most favorite advanced / master diver student, he was the one who had the free-flow on his SP reg. I am thinking it was more an over-breathing anxiety problem, but they were at gilboa in Feb. getting the deep dive completed. My guess is...it was damn cold, first deep dive, and the bottom temp couldn't have been much better than low 40's. Panic attack, overbreath the reg...shoot to surface. Also, how often do you see 38 deg. for any length of time?

 

[TheDecoStop]

I just opened the manual, and it states that... systems intended for use in temperatures below 50 degrees F must employ regulator sets proven for cold water diving.

The MK25 has TIS (Thermal Insulating System) which is supposed to be an antifreeze system for the first stage.

There is also a bit more info on page 1-20 for cold water diving. They basically say that even though the S600 has been designed with some anti-icing technology, you should always have your setup on redundant valves when diving in extremely cold conditions. And to make sure to control your air consumption as to not accelerate the freezing process.

TDS

 

[sylvester]

I read em a while ago, granted I cant regurgatate what those specs are from the top of my head. I remember something about 70 deg water, I will claim ignorance thinking hummmm sp mk25/s600 high end quality regulator should suffice for rec diving. I have only been in 70 degree water in a pool.

The instructor who was using my octo is my LDS owner.

 

[-BlueHole-]

I heard also of some divers who had problems with freezing mk.20-25.
I use one as secondary and I never had probs. ( probably cause I dont breathe it )
Probably SP put a new model (mk 25 AF) on the market just one year after the exit of the mk 25 because of the probs in cold water.
Personally I switched to a Poseidon as primary, and adviced my girlfriend (who dives with me) to not buy a SP...
Since we dive mostly in cold water as soon as can afford I'll switch to a poseidon also for secondary and rely my SP to deco bottles

 

[Big-t-2538]

Something you might want to try is not pressurizing the regs until you are in the water for a minute or two...