Scubapro - Please help to choose

[blues_diver]

Hi All, apologies for starting another question on which regulator to buy! I have read so much on regulators that my brain felt like exploding! This will be my first regulator and hope it will last me for a long time...

One think for sure, I am pretty much sold on Scubapro reg. All I need to know is which one will best suit me:
1. MK25/S600 or G250HP
2. MK17/S600 or G250HP
3. Mk2+/R295

My dive profile:
- All warm water diving.
- Recreational depth < 40m/120ft

Many thanks in advance!

 

[grantctobin]

Because of the warm water, you do not necessarily need the cold water capability of the MK17/S600. Any of these regs will last for a very long time. The MK2 is unbalanced, meaning that it will breathe OK at depth, but will not give the performance of the MK25. The Mk2 is a bulletproof reg and will take a beating (commonly used as rental regs).

The G250V will be coming out shortly, which will replace the G250HP (already has in Europe). It has a metal air barrel, meaning that it will breath with moisture helping eliminate dry mouth. The G250V is identical to the old Graphite G250. IMO, For SP, this is a step in the right direction because some of their old designs are better than their current ones.

It depends on your budget, the MK17/S600 will work for anything, has decent routing, and is a bit cheaper than the MK25. The MK25, has all of these features, but some say breathes a bit better. The MK2 in unbalanced, and breathes not as great, but will last a while and will suit your needs.

As far as a decision between the G250 and the S600, its entirely your choice. Internally, they are identical but the G250 is a larger case. The S600 also costs about 60 dollars more.

 

[DA Aquamaster]

In my experience with using very easy breathing D400's on both Mk 25's and Mk 17's used side by side on a doubles set up, there is no difference in how the second stage performs in terms of flow rate, response time or inhalation effort. I switched from Mk 20's and Mk 25's to Mk 17's a couple years ago and have never regretted it.

The Mk 25 does have a higher flow rate (300 SCFM) than the Mk 17 (177 SCFM) but the extra flow rate is massive over kill as even the best performing second stage will not flow more than 65-70 SCFM. In general anything over 150 SCFM will provide all the air you and another diver would ever need in any recreational, deep or technical dive situation.

Just as importantly the Mk 17 has a very fast response time and has no more lag or drop in intermediate pressure than a MK 25. Perhaps more significantly, the Mk 25 is normally set with an IP on the low end of the normal range - around 125 psi - to improve reliability in very cold water by reducing flow rate at the first and seccond stage slightly. In contrast every Mk 17 (a fully sealed and virtually freeze proof design) I have seen has had the IP set at the high end of the range - around 145 psi. This does boost first stage flow rate slightly but more importantly it also boosts the second stage flow rate fairly significantly. In effect this commonly found difference in tuning creates a situation where a given second stage model will theoretically perform better on a MK 17 than on a Mk 25 under deep, demanding conditions.

In my opinion, the Mk 17 G250 offers the most bang for the buck while the Mk 17 S600 and X650 offer identical performance and a virtually identical price.

For the diving you intend to do a Mk 2+ R295 is a very good regulator and would get the job done. But it will not breathe as nice as the other choices and if you ever borrow one of those, you'd find yourself unhappy with your Mk 2 R295 on your next dive. The main advantages of theMk 2 is its super simple and super reliable design, it's low cost and its fairly compact size (although the Mk 17 is a close second in the size and weight department). I still use the first reg I ever bought, a Mk 3, (predecessor to the Mk 2+) after 25 years of use as one of my deco regs.

 

[blues_diver]

Thanks to both of you for the quick response!! That's why I like this Board so much.

I am leaning towards the MK17 as the middle ground (in terms of cost), as I don't dive frequently but I want my own gear. But I always have this conception that piston (MK25) works better than diaphram (MK17) or is this a misplaced believe?

Finally, any idea if the G250V is worth the wait? I saw that it is already available in the Scubapro UK but not in Asia, my part of the world.

And while I was at it, I saw now they have the MK19! It is getting confusing, should stop researching so much...

Apologies for the flurry of questions.

Cheers

 

[DA Aquamaster]

The Mk 19 is a Mk 17 with a swivel turret. Performance is gossly the same although the Mk17 uses a pair of venturi assisted ports while the Mk 19 will need to route the air forward to the LP port turret.

In the past I would have agreed that piston regs had the edge over diaphragm regs, but I changed my mind after diving and working on the Mk 17.

 

[grantctobin]

The Piston design allows for a higher flow rate, but the diaphragm is better in cold water. If you ever advance into technical diving, Piston regs handle being flooded better in case of emergency.

If you really want the G250V, you might as well go on ebay and find an older G250 (they are identical, except for the style). The MK19 is a MK17 with a swivel, which allows for better hose routing. With any of your choices, you will be content. Although, like DA said, you wont like the MK2 after you breath a MK17 or MK19


Looks like DA beat me to it.

 

[blues_diver]

Thanks again guys, but it is getting a bit too technical for me with terms like "venturi assisted ports" and "LP port turret". In any case, the info is much appreciated

One final question - for recreational depth (say 120ft or less), does it matter that Piston reg handle being flooded better?

thanks

 

[grantctobin]

sorry to confuse you, flooding a reg is dangerous, but its a technique that is used in an emergency for technical diving. That should not affect your choice at all.

 

[blues_diver]

sorry to confuse you, flooding a reg is dangerous, but its a technique that is used in an emergency for technical diving. That should not affect your choice at all.

No worries. Out of curiosity, what kind of emergency in technical diving requires you to flood your reg?

 

[grantctobin]

When you are deco diving, if you have a deco reg fail, you have a need to switch to a different reg. This is rare, but if it occurs, you can either use your backgas reg or by using another deco-bottle reg. This is why some people keep all of their regs O2 cleaned. A flooded reg will require an overhaul later, but its this, or well... you get the point.