Question Is a Mk25 overkill for recreational tropical water dives?

[Karlstumke]

I use mk25 with A700carbon. Great reg. I use Air 2 and AI so only have two hoses which is ideal for travel and keeping things neat and tidy. I do think my Apeks breathes a bit easier but way heavier

 

[USdiver1]

OP is looking for a regulator that can take abuse on the maintenance side and will safely work for light recreational diving. He suggested the SP Mk2 as well as the SP Mk25 and several SP diaphragm first stages like the Mk11 and Mk17. He is seeking SP, which as we all know is good, reliable equipment.

All of the listed first stages will provide enough air for light recreational diving, the least complex and arguably most robust of all of these is the SP Mk2, an unbalanced first stage that has been in production for sixty years in one form or another by SP. It is a piston rather than a diaphragm first stage, that has the advantage of fewer moving parts, and is incredibly tough. I'd say the Mk2 is the Keith Richards of first stages, able to survive a nuclear strike and co-exist with the cockroaches when the rest of civilization lies in ruin. A Mk2 can go for decades without servicing, and is very field serviceable, it is the AK47 of the regulator world if you don't follow rock & roll.

Are the others overkill? Maybe in the sense that they are more complex. I have a Mk2 coupled with a G500 [balanced second stage] that serves as a backup regulator in my gear bag. Why? because it will always work, or can be made to work in just about any location, with little more than a screwdriver.

 

[BoltSnap]

OP is looking for a regulator that can take abuse on the maintenance side and will safely work for light recreational diving. He suggested the SP Mk2 as well as the SP Mk25 and several SP diaphragm first stages like the Mk11 and Mk17. He is seeking SP, which as we all know is good, reliable equipment.

All of the listed first stages will provide enough air for light recreational diving, the least complex and arguably most robust of all of these is the SP Mk2, an unbalanced first stage that has been in production for sixty years in one form or another by SP. It is a piston rather than a diaphragm first stage, that has the advantage of fewer moving parts, and is incredibly tough. I'd say the Mk2 is the Keith Richards of first stages, able to survive a nuclear strike and co-exist with the cockroaches when the rest of civilization lies in ruin. A Mk2 can go for decades without servicing, and is very field serviceable, it is the AK47 of the regulator world if you don't follow rock & roll.

Are the others overkill? Maybe in the sense that they are more complex. I have a Mk2 coupled with a G500 [balanced second stage] that serves as a backup regulator in my gear bag. Why? because it will always work, or can be made to work in just about any location, with little more than a screwdriver.

You are neglecting other facts the OP mentioned. He isn't going to fight a nuclear war, or war of any type, nor go to live in secluded island on the edge of the universe. The MK25 has been in production and use for around 25 years now and has been upgraded over these years for the better. It is the standard that all others try to compete against in performance, reliability, etc. etc.

You are also forgetting, although it has been mentioned above, that once you leave the MK2 standard configuration with the standard second stages SP bundles with it and buy à la carte, you are going to pay a lot more where it doesn't make any sense to do that.

 

[KeelsonGraham]

Hi all, this is the OP. Thank you for some really great insights. It seems that everything from the Mk2 upwards will do more than a good job underwater in my circumstances. So, the choice now is which reg, or type of reg, will best survive the abuse of a sailboat in the tropics. The post-dive rinsing thing is on my mind. Even a gallon bucket of water is a lot for a sailboat. The Mk2 piston seems to get your vote as bullet proof. The Mk17 is tempting because it’s environmentally sealed.

 

[scrane]

That is a very dismissive and inaccurate answer. Just not helpful as it adds no value to the OP.

The Mk25 is better than many other 1st stages and perhaps not as good as a few.

The purpose of the first stage is to provide a relatively stable intermediate pressure with sufficient flow reliably. This is not a high bar and any popular first stage can do it. Beyond this there are features like port layout, balanced/unbalanced, piston/diaphragm,
sealed/unsealed, ease of maintenance, temperature tolerance, &etc. But to say the Mk25 is better than many other regulators is a stretch and has more to do with brand loyalty and bragging rights.

 

[DreadnoughtNH]

A. That set is unlikely to go wrong, reducing one potential failure point so that we can concentrate on safe diving practices.

It is robust. Check.

B. It breathes easily (good for tired old farts)

You like how it breathes. Check.

C. It can be easily serviced in the Caribbean.

You've done the research for servicability. Check.

D. It probably has the best chance of withstanding the rigours of boat life, living 24/7 in a corrosive environment without unlimited freshwater for post-dive soaking.

Double down on robustness. Check.

I’m happy to spend the cash if there’s a real benefit in doing so, but I don’t want to spend it just for the hell of it.

You have a boat so cash really isn't the problem here.

Help and advice would be warmly welcomed!

I don't think you need advice! You've clearly done the research. Go get the Mk25s and go have fun!

 

[Still Kicking]

The post-dive rinsing thing is on my mind. Even a gallon bucket of water is a lot for a sailboat.

Keep a dedicated gallon of water in a jug set aside for rinsing and reuse it. The incremental amount of salt that gets added every rinse is negligible until you can refill the jug when you stop for a resupply.

 

[BoundForElsewhere]

Keep a dedicated gallon of water in a jug set aside for rinsing and reuse it. The incremental amount of salt that gets added every rinse is negligible until you can refill the jug when you stop for a resupply.

I wonder if pee would work as a rinse.

oh wait, he's putting that in his mouth. nevermind.

 

[davehicks]

The purpose of the first stage is to provide a relatively stable intermediate pressure with sufficient flow reliably. This is not a high bar and any popular first stage can do it. Beyond this there are features like port layout, balanced/unbalanced, piston/diaphragm,
sealed/unsealed, ease of maintenance, temperature tolerance, &etc. But to say the Mk25 is better than many other regulators is a stretch and has more to do with brand loyalty and bragging rights.

Every car on the market will get me to the grocery store. To say that a BMW i5 is better than Geo Metro is brand loyalty and bragging rights.

 

[BoundForElsewhere]

Every car on the market will get me to the grocery store. To say that a BMW i5 is better than Geo Metro is brand loyalty and bragging rights.

umm, but it kind of is better, isn't it?

I think I'd rather get hit by another car if I were in a BMW than a Geo.