Cold water regulator freezing question ...

[scuba393]

I'll be diving in the North East (NJ and NY) late spring through early fall. For this time frame, should I be concerned with purchasing a reg that performs well in cold water (i.e. SP MK17 vs. MK25), or is water temp not really an issue and should buy a better breather (i.e. SP MK25 vs. MK17)?

 

[horsediver1]

I have each of the models, and do a substantial amount of ice and cold weather diving. The MK 25 is an excellent reg but will freeze and free flow as I found out experimenting in 34 degree water on a 25 degree air temp day. The MK 17 is designed for the cold and extreme condition NOT one incident on free flow or performance. The MK 25 can handle 45 plus water very well.

 

[akscubainst]

Both regs will work fine in cold water if tuned correctly. I've been diving a MK25 S600 for years in 34F or less water with air temps down to -3F without any problems.

 

[scuba393]

Makes you wonder if all the cold water freezing/free flowing MK25's you hear about are more of a user error by not tuning properly vs. design problem ...

 

[ScubaSteve]

Makes you wonder if all the cold water freezing/free flowing MK25's you hear about are more of a user error by not tuning properly vs. design problem ...

I have heard the stories from some very experienced equipment techs and experienced divers so I would have said no. But, If someone in Alaska is diving an MK25 successfully, then perhaps something else was happening. Bottom line is, the MK17 is a top notch reg so I would not hesitate to use it over the MK25. In fact, I still would just in case.

 

[akscubainst]

There's no design problem with a MK25. Users just need to make sure that the tech working on the reg tunes it (and the 2nd) to Scubapro's cold water specifications. The MK25 is a fantastic reg as is the 17.

 

[horsediver1]

To erase any doubt I am a Scubapro Certified Tech. The MK25 that free flowed in the above conditions was brand new out of the box. Immediately my first thought it was out of spec. however it was spot on when I benched it for all the tests and balance. The 25 was not specifically designed for extreme conditions it is an excellent breather, the issue is the design itself focused on with certain atmospheric conditions water temp, air temp and humidity the venturi may develop an icing condition causing the free flow.

Bottom line is the 17 is specifically designed for extreme conditions and may breath a little drier but if I only was going to buy one reg I would choose the 17 based on where the original poster lives.

 

[a22shady]

I live in NJ and dive here year round. I would definitely go with the MK17 over the MK25. I own both 1st stages and there really is no difference in breathing/performance or at least not that I could tell. The MK17 just gives you the added safety of being a sealed diaphragm and makes it less likely to free flow. For the 2nd stage i use the G250V as it has proven itself very well. I also own the S600 and when diving in colder waters is more susceptible to free flow then the G250V (So I heard seen a 2 free flow but not sure of exact cause) . So make sure your second stage can handle cold waters also. MK17/G250V is an awesome any water set-up. I also dive the Atomic M1's and have not had any issue with these either.

As others have said there is things you can do to most reg's to make them suitable to dive colder waters such as reducing IP, Keeping the adjustment low, not pre breathing. But for me what works best is get a reg thats desighned for it. I dove all winter long. Tested air on surface did the dive sat out did another no issues. Waters were around 38F was the coldest

 

[hypertech]

I had some reg problems ice diving until I switched to the XTX200. The Apeks is worth considering.

 

[scuba393]

I have been looking at the XTX200 as well as the AL Legend LX. For some reason, my LDS is pushing the MK25 over the MK17 ... so many choices and opinions, it can make your head spin.