Rumor: Scubapro Mk17 to be discontinued soon?

[Geo7]

Since this thread is by nature a Mk17 appreciation thread of sorts, I'll take the liberty of posting these pics and one idea:

The first two iterations of the Mk17 I am aware of come with two parallel LP ports and one HP port that is angled towards the diver. Not my favorite hose routing to angle the HP port (or any hose port) towards the diver. The Mk17-EVO has a different port arrangement (see pics) and allows me a flatter, more parallel hose routing. The ideal reg for me in that regard would be the Apeks FSR and Dive Rite FT1 with all parallel ports (although my favourite is now a compact, light, balanced piston first stage with 5th port).

Anyway, what would be cool would be an assymetric port arrangement that I think I have seen on some Poseidon 1st stage: I'd arrange the ports like the Mk17-EVO on the divers left hand side, but like the Mk17-classic on the divers right hand side. That would be elegant, if the stage can be flipped upside down to give you either port arrangement.

I wonder what others prefer, and seem to remember some DIR configurations benefited from the HP hose angle the Mk17 classic has? Clearly there is no one way to cover all configurations, but perhaps assymetric port layout would provide the best of both worlds?

 

[pwfpaulo2]

what´s up folks,

let me ask you, does anyone have some experience diving the MK17evos to the range of 70~100m (200 to 300ft)? I am about to replace my 25's with the last two pairs of 17evos available from my local dealer. No one around here uses them in this kind of diving, in fact the 17 are barely seen around here. wishing to get some thoughts about it.

tks!!

 

[Geo7]

I can't point to specifics right now, and certainly don't dive that depth myself, but yes, people dive the Mk17 that deep and deeper. The limitation in sealed diaphragm 1st stages is 1) IP that is overcompensated for depth, and 2) deformation of the load transmitting pin. We had a thread on SB that showed a graph that revealed the Mk17 to have a wider range than common regs.

 

[pwfpaulo2]

I can't point to specifics right now, and certainly don't dive that depth myself, but yes, people dive the Mk17 that deep and deeper. The limitation in sealed diaphragm stages is 1) IP that is overcompensated for depth, and 2) deformation of the load transmitting pin. We had a thread on SB that showed a graph that revealed the Mk17 to have a wider range than common regs.

I'll read it, interesting. Everyone here dives mk25 for this depth, including me, till now.

 

[grantctobin]

what´s up folks,

let me ask you, does anyone have some experience diving the MK17evos to the range of 70~100m (200 to 300ft)? I am about to replace my 25's with the last two pairs of 17evos available from my local dealer. No one around here uses them in this kind of diving, in fact the 17 are barely seen around here. wishing to get some thoughts about it.

tks!!

Anecdote, but I've had mine to 100M without issue, both for CCR and OC use.

 

[Geo7]

So this graph would indicate that the workhorse Apeks DS4 is good to 200m but would get very high IP (intermediate pressure) much sooner than that (which solenoids or balanced second stages may be able to deal with depending on what you have). The graph indicates that Mk17 keeps the IP impressively stable (against depth) until 250 meters, and then it decreases.

So short answer: no worries that I can think of.

Note: There were many threads on Scubaboard about so called "overbalanced" 1st stages (a marketing term), which refers to imperfect compensation of IP against ambient pressure, i.e. depth in sealed 1sts. That's a result of the assymetric load transmitter. Not to be confused with real balancing of IP in a 1st stage against tank pressure.

And for our entertainment:

If you wanted to go deeper than those depths, and the water is warm, you could just remove the environmental seal and avoid the problematic with the load transmitter and changing IP with depth. The US4 comes unsealed, and the Mk11 is an unsealed Mk17, well apparently a slightly detuned Mk17 (thicker diaphragm with less seat travel).

And to make things even more complicated, some guys on the CCR forum dive Fathoms and KISS CCRs with Mk17s that have a steel or delrin plate instead of the environmental diaphragm, in order to keep IP locked at what it is at the surface, eaning it is un-compensated against depth (since MCCRs need this). Some even get a stronger spring for a higher IP so they can go deeper than our usual IP would allow.

 

[Geo7]

I'll read it, interesting. Everyone here dives mk25 for this depth, including me, till now.

If you want to go to 3000 m (9842 feet), the Mk25 might be your choice: Scubapro 1st Stage used in experiment works flawlessly at 3000M depth

 

[pwfpaulo2]

Yes Geo7, I know about this "concepts" lets say, about "overbalancing" and natural IP change due to tank pressure, but it is not my concern right now, w/ this regs.

what I look for is exactly what grantctobin said, an experience of one who actually had breathed from a mk17evo at those depths, how it feels, if its ok, if its nice to dive with. As no one in my folks uses them. (don't ask why, have no idea).

I do not dive OC, this deep very often (100m), it´s about 6 to 10 times a year, in Tx courses mainly. 50 to 60 is much more frequent, as it is the depth of our local quarry.
Removing the enviro seal, don't seems logic, if so I would just keep my 25's right? But I get your point, it would be an option.
The point of the 17evo is exactly to keep the dirt out, it's what I need.

tks for the comments, I´ll get this two pairs that are available, (before it vanishes) and pair with G260's. Will be a nice set up for long years.

 

[pwfpaulo2]

Mk25 is a monster... it´s used in research submarines too. They are my main set till now, but they get too much dirt in it, our quarry has a suspended sediment that impregnates inside the regulators.

 

[grantctobin]

Mk25 is a monster... it´s used in research submarines too. They are my main set till now, but they get too much dirt in it, our quarry has a suspended sediment that impregnates inside the regulators.

I’d probably get MK19 rather than MK17 because of the swivel, but neither will be inappropriate, especially if you get a good deal with the MK17.