Scubapro MK18 and MK25 Questions

[realdiver7]

Trying to find out if anyone has any experience and/or knowledge of the Scubapro MK18, especially when compared to the MK25. I think the flow rate of the MK18 is listed as almost half of the MK25, but which one breathes easier at depth and under strenuous activity like working underwater?

I like the diaphram design because I dive in salt water and like the idea of no internal mechanical parts being exposed to salt. However, if the MK25 is easier to breathe from with an S600 2nd stage, then I would consider it. Also, I do not normally dive in water below 50 degrees, but the water can be silty at times.

Since the MK18 is no longer available in the US and is not in the 2005 catalog, I also wonder if the cost to service it is comparable to the MK25, and if parts are readily available. Have there been any problems with the MK18, especially with the revolving turret? Any advice would be greatly appreciated.

Thank you.

 

[DA Aquamaster]

Flow rate for the Mk 16 is 170 scfm compared to 300 for the Mk 25. The Mk 16 is essentially idencial to the Mk 18 with the exception of the use of a swivel turrent on the Mk 18. Given that the air is routed forward to the turret rather than out the sides through venturi assisted high flow ports, I suspect the flow rate on the Mk 18 could be slightly lower than the flow rate on the Mk 16.

But I don't think it makes much difference as anything around 100-110 scfm (about the flow rate of the Mk 10) is more than enough air for nearly any situation.

The Mk 16 and Mk 18 share the same internals and the same annual service parts, so parts availability should not be an issue unless you break something really odd.

 

[realdiver7]

I appreciate the good info. Since the flow rate of the MK25 is that much higher than the MK16/18, does that mean the MK25 will breathe easier with strenuous activity underwater?

Thanks.

 

[OE2X]

For what it is worth I've huffed and puffed on my MK25's and S600's. All of them (6) have performed flawlessly.

I just recently got a pair of Apeks ATX 200's that breath easier than the S600's. I got these for an upcoming trip where the air temps will be around freezing.

Bottom line unless you are a real hoover, then you will love the 25/600 combo.

 

[hex92]

I have done a side by side comparison between the Mk18/G250 and the Mk25/S600 in 90+ feet of water. The 25/600 combo does breathe noticeably easier. Not alot easier, but you can tell the difference.

Now the question you need to have answered is this: is the 25/600 combo worth the extra $200?

When I answer that quesiton I will buy another set of regs.

FWIW I own a Mk18/G250 and I love it. I bought it locally for $340. Worth every damn penny.