I will absolutely concede to anyone that the S600 is a great 2nd stage reg in water 50 degrees and above, at least from my experience. Just looks like to me that I need a different tool for my deeper and colder Great Lakes diving. Poseidon Jetstream/Odins appear to be engineered for that type of environment, so they will become another tool in my "toolbox". Now that I know the limits of my SP regs, I will use them in the warmer settings. Genesis: You are right on the money here with your assessment. The problems you explain on the piston 1st stages is why early on I went with diaphragm 1st stages instead.
SP MK25/S600 Freezeups
- Thread starter sylvester
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are just fine seconds, even in cold water. The S600 is really just the G200B's balanced poppet mechanism with a prettier face; SP really only has two internal mechanisms on seconds - an unbalanced (R190, R380, etc) and the balanced ones (S550/600/etc), if you don't count their "Darth Vader" reg (the 400, which I haven't had apart)
The SP diaphram regs are ok, but (IMHO) unnecessarily complex - probably to avoid patent infringement problems. If you want a diaphram reg, but an Apeks first.
The SP diaphram regs are ok, but (IMHO) unnecessarily complex - probably to avoid patent infringement problems. If you want a diaphram reg, but an Apeks first.
Keepin people posted, 123' dive to the bottom of Gilboa Quarry in Ohio, 40F water and the Poseidon Jetstream/Odins just got better the deeper I went. WOW! I'm sold.. My Scubaho's are consigned to warm-water weeniedom. Only complaint about the Poseidons, replace the mouthpiece with a SeaCure II, and all will be well.
Laser
Guest
It's been my understanding that performance was never a key issue with the poseidons, although I've heard them described as *forcing* gas into your mouth. It's always been a service issue that I've heard people left them for another brand. Hope they give you great dives for a long time.
Just curious....you do that 123ft at Gilboa on doubles or a single?
Just curious....you do that 123ft at Gilboa on doubles or a single?
Nah, they don't "force" the gas at me, but the gas is there if u want it or need it. They breathe "differently", so one may have to get used to that. They breathe rougher at shallow depths, but smooth out the deeper you go, with them hitting their "sweet spot" at around 90 ft. I carry a 30 cu ft sling bottle anytime I go into cold fresh water greater than 60 ft (personal conviction), along with my 120 cu ft single. Its my best dive buddy 
hehe .Now that I have regs geared for this environment, feel the safety margin has been further increased. Servicewise no worries have a good LDS with a good tech (He dives Jetstreams too)
hehe .Now that I have regs geared for this environment, feel the safety margin has been further increased. Servicewise no worries have a good LDS with a good tech (He dives Jetstreams too)
Went out this past weekend to Lake Michigan to dive the Milwaukee Car Ferry using my MK25AF/S600. We descended down the bow morring line and followed the line over to the pilot house. (117ft, 32 degrees according to me computer) We made it around the pilot house and I headed back to take a look under the overhanging portion when I started hearing something. It was weird at first, you get into the normal pattern of sounds, inhale, exhale... Wait - why am I hearing exhale when I'm inhaling...?!?!?!?!? Much like a pot of water on the stove it grew into a full boil... Not quite the "drink from the firehose" I was expecting based on other peoples descriptions, nor my own expectations based on purging the second stage to simulate. I was loosing air from the tank, but could still breathe... No need to panic - I've got three other folks very close by and I can see them all. I swam up to my buddy and got his attention - gave the out of air/let's share combo, got a perplexed look back - then showed him the bubble stream shooting out of the second stage - he got the idea, unwrapped and offered his primary (7ft hose). We hooked arms and began the ascent - a tad on the fast side, but definately not a bullet ride to the surface. The freeflow stopped around 20ft - once we got above the thermocline my computer read 400+ psi. I orally inflated my BC and gave a big ole "OK" to the two boats nearby when I heard someone say "that was alot of bubbles". In the tussle I lost yet another snorkle - I eventually gave up on the swim on your back surface swim and used the reg back to the boat.
Once on board the Captain did his best - needless to say I was a little spun up. We talked about regs - every few minutes he was checking up on me - I think likely to see if our ascent was too fast and monitor for DCS. No problems - we spent two hours on the surface and suited up to return. The Captain loaned me his Abyss for the second dive and we went without a hitch. (For whats its worth - he said he routinely takes it to 300ft. on trimix)
I have an MK25TA and an MK25AF - I took them both into a SP dealer to have them tuned for Cold Water diving. They set one to an IP of 125 and the other to 128 (I'll hafta request them to pull a shim when I do my annual service to get any lower).
Previously the harshest I have had these regulators to 80ft, 37 degrees no problem. I've gone deeper, 127 feet - but at 82-83 degrees in the Caymans.
Once on board the Captain did his best - needless to say I was a little spun up. We talked about regs - every few minutes he was checking up on me - I think likely to see if our ascent was too fast and monitor for DCS. No problems - we spent two hours on the surface and suited up to return. The Captain loaned me his Abyss for the second dive and we went without a hitch. (For whats its worth - he said he routinely takes it to 300ft. on trimix)
I have an MK25TA and an MK25AF - I took them both into a SP dealer to have them tuned for Cold Water diving. They set one to an IP of 125 and the other to 128 (I'll hafta request them to pull a shim when I do my annual service to get any lower).
Previously the harshest I have had these regulators to 80ft, 37 degrees no problem. I've gone deeper, 127 feet - but at 82-83 degrees in the Caymans.
scubahorse
Guest
I wouldn't dive with a piston first stage without a enviormental kit, when the water was that cold.
Yup sounds like more S600 problems. The problem isn't your first stage, as I saw another S600 blow its cookies in Tobermory on someone at 135 ft. That's why i switched to Poseidon Odins, the problem just disappeared after that. Now all said, I have a MK18 scubapro 1st stage and it is a great 1st stage. I'm going to hookup a a Poseidon odin second stage to it, after we adjust the IP on it. Gonna use my S600 on this second set of regs as an octo.
Here's how to know if your S600 is going to freeze. It begins as a light hissing sound with a small flow of gas out of the reg. Continue to breathe it, and it will evolve into a full freeflow. I won't use it as a primary in cold fresh water now. Period.
Here's how to know if your S600 is going to freeze. It begins as a light hissing sound with a small flow of gas out of the reg. Continue to breathe it, and it will evolve into a full freeflow. I won't use it as a primary in cold fresh water now. Period.
Thanks for the feedback - this makes a little more sense why the shop tuned the IP down.
Question for you - I routinely dive with both adjustable settings on the second stage wide open: VIVA set to maximum and the Inhalation Adj. knob all the way open.
Would tuning these down have made any effect during the freeflow...?
What most people think is a second-stage freeze is usually really a first stage freeze. The piston freezes in its bore, and as a consequence the seal cannot be made between the piston end and the seat. The pressure rises in the hose, and the second stage opens to vent the pressure (a good thing too, otherwise you would eventually get a hose explosion!)
For a second stage to actually freeze you need frozen water EITHER on the poppet assembly OR in the gas stream coming from the first stage. If you get it in the gas stream, then you have a HIGH degree of moisture in the air in your tank - the fix for that is to buy your air from a shop that cares about the dewpoint of what they pump! (Never mind that the water in the gas will do ugly things to steel tanks.)
If its happening in the second stage poppet assembly, then you're hosed. That CAN happen on plastic regulators (without a metal air tube) as plastic has nearly-non-existant thermal conductivity and mass, and as such your exhaled air does not warm the parts significantly. The gas coming into the stage is quite cold. You exhale, the gas in the reg is below freezing, and it flash-cools and freezes the moisture in your exhaled breath. Bingo - a stuck mechanism.
For a second stage to actually freeze you need frozen water EITHER on the poppet assembly OR in the gas stream coming from the first stage. If you get it in the gas stream, then you have a HIGH degree of moisture in the air in your tank - the fix for that is to buy your air from a shop that cares about the dewpoint of what they pump! (Never mind that the water in the gas will do ugly things to steel tanks.)
If its happening in the second stage poppet assembly, then you're hosed. That CAN happen on plastic regulators (without a metal air tube) as plastic has nearly-non-existant thermal conductivity and mass, and as such your exhaled air does not warm the parts significantly. The gas coming into the stage is quite cold. You exhale, the gas in the reg is below freezing, and it flash-cools and freezes the moisture in your exhaled breath. Bingo - a stuck mechanism.
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