Help with Decision

[mick allein III]

DaleC thanks. I regularly sling an 80. I get it. I am going to have to go to SM or BM. Kind of leaning toward BM. Thanks all for your help.


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[Searcaigh]

I was interested in both Dumpster Divers post and rx7divers earlier post. Dumpster Diver seems to do deco on a big steel 149. Do you all think that a y valve on steel 149 with reg for breathing and bc and a reg for the Drysuit inflator with a 40 or 80 cf pony and. Deco bottle would be safe for nonpenetration dives into 140-150 range?
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For diving to 140-150 ft what deco gas would you be planning to carry?

If 50% then you are not going to be able to use that until you reach 68 feet (rough calculation from my metric brain), so what are you going to breath if some something goes wrong at 140 feet?

Go for doubles with an isolated manifold and sling a 30 or 40 cu ft deco with 50% and you are good to go.

If not planning deco and only need an appropriate sized bail out bottle sufficient to get you to the surface as determined by your SAC rate under stress, with the same contents as your back gas, air would be your choice I guess.

Dumpster Diver can probably CESA to a depth where his deco bottle gas will not kill him given his experience, and most likely one of his ancestors was a fish

 

[dumpsterDiver]

I was interested in both Dumpster Divers post and rx7divers earlier post. Dumpster Diver seems to do deco on a big steel 149. Do you all think that a y valve on steel 149 with reg for breathing and bc and a reg for the Drysuit inflator with a 40 or 80 cf pony and. Deco bottle would be safe for nonpenetration dives into 140-150 range?


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I have not used a dry suit in maybe 30 years,, so keep that in perspective. I have a hard time seeing what benefit you are envisioning from a y-valve. It will require you to take two first stages that are mounted behind your neck. That doubles the chance that you will have a failure back there.

If you are carry a 40 cu-ft or 80 ft bail out bottle, then what benefit are you getting from the Y-valve? Does the benefit offset the increased cost, maintenance and additional complexity (and additional failure point)?

If you are NOT using a y-valve and have a total failure of the main tank, and you can not use any of it, why can you not come up and even do (a little) deco on the big pony? If you have a failure at depth, can you not ascend without further inflating your dry suit?

I dive with a guy who has a y-valve on his big main tank, a 40 cu-ft bail out bottle (air) back mounted and upside down and a 40 cu-ft deco bottle back mounted and upside down (50%). I don't really see the value of his y-valve configuration and it looks like a cluster to me, but that is what he uses.. for solo dives on air to 230 ft or so.

This video shows his rig from around 6:30 and on. This was a 185 ft - air dive with deco. there is some self-video of me around 1;30 showing my rig of a big steel, a 13 cu-ft pony and i am wearing a 19 cu-ft oxygen slung deco bottle.

You don't need much air to get in deco at 150 ft, so if you are taking a big tank, you are going to be in deco. If you are going to be doing much deco, most people are using 50% , 80% or 100% bottle for deco - so you should probably figure how you are gonna manage, 3 tanks.. that is how i see it anyway.

I'm NOT promoting the configurations or practices shown in this video... I show it simply to provide an idea what it may look like, if you should do something similar.

Oh yeah, I'm wearing a snorkel, using an Air 2, wearing a scuba pro BC (not a BP/W) and probably 5 other things that will give some people heartburn.



[video=youtube;uZJ0byuTVqU]https://www.youtube.com/watch?v=uZJ0byuTVqU[/video]

 

[waterpirate]

Side mount in rough seas is exactly what you do not want. Handling tanks on a line that may be going up and down as much as six feet is problematic IMHO. It also puts you where you really do not want to be, under the boat that is also going up and down six feet. It is a whole nother story in the scenario Ron described.
YMMV
Eric

 

[rx7diver]

I have not used a dry suit in maybe 30 years,, so keep that in perspective. I have a hard time seeing what benefit you are envisioning from a y-valve.

dumpsterDiver,

Keep in mind the OP is referring to Great Lakes diving. The main benefit for a "Y" or "H" valve on the single tank is to address a free-flow (shut down one reg, but still have the ability to both breathe off the back tank and inflate something using the back tank), I think. Not too long ago I posted here a download from my air integrated computer showing how quickly a free-flow can deplete a cylinder through a high-performance regulator even if an hasty ascent is begun almost immediately, even from recreational depths.

Air sharing benefits, too (though admittedly this is a less likely benefit since each diver probably will be carrying his/her own bailout), since both divers breathing from a single back tank but using different first [sic] stages are less likely to induce a free flow.

Your points about additional equipment are certainly relevant. However, one's kit doesn't have to look like a cluster (I've posted before a pic of my Scubapros on a "Y" valve on my 72 attached to my Freedom Plate); I service my own Scubapro regs (though not my Poseidons); and, perhaps most important here, and something I didn't think about until just now, is, I went the other way around: I "de-teched" or "un-teched," going from tech to rec. So I already had the single back tanks (separated my doubles), the regs (from my doubles and my deco bottles), the bailout bottles (repurposed my deco bottles), and a singles BC. I *needed* to purchase only an OMS "H" valve part to fit my now separated OMS doubles manifold on my HP 120, and a Sherwood "Y" valve to fit my 3/4" PST steel 72.



Safe Diving,

rx7diver

 

[rivers]

I dive with a guy who has a y-valve on his big main tank, a 40 cu-ft bail out bottle (air) back mounted and upside down and a 40 cu-ft deco bottle back mounted and upside down (50%). I don't really see the value of his y-valve configuration and it looks like a cluster to me, but that is what he uses.. for solo dives on air to 230 ft or so.

Ahh the space shuttle configuration

 

[dumpsterDiver]

dumpsterDiver,

Keep in mind the OP is referring to Great Lakes diving. The main benefit for a "Y" or "H" valve on the single tank is to address a free-flow (shut down one reg, but still have the ability to both breathe off the back tank and inflate something using the back tank), I think. Not too long ago I posted here a download from my air integrated computer showing how quickly a free-flow can deplete a cylinder through a high-performance regulator even if an hasty ascent is begun almost immediately, even from recreational depths.

Air sharing benefits, too (though admittedly this is a less likely benefit since each diver probably will be carrying his/her own bailout), since both divers breathing from a single back tank but using different first [sic] stages are less likely to induce a free flow.

Your points about additional equipment are certainly relevant. However, one's kit doesn't have to look like a cluster (I've posted before a pic of my Scubapros on a "Y" valve on my 72 attached to my Freedom Plate); I service my own Scubapro regs (though not my Poseidons); and, perhaps most important here, and something I didn't think about until just now, is, I went the other way around: I "de-teched" or "un-teched," going from tech to rec. So I already had the single back tanks (separated my doubles), the regs (from my doubles and my deco bottles), the bailout bottles (repurposed my deco bottles), and a singles BC. I *needed* to purchase only an OMS "H" valve part to fit my now separated OMS doubles manifold on my HP 120, and a Sherwood "Y" valve to fit my 3/4" PST steel 72.

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Safe Diving,

rx7diver

Yeah but are you using a pony bottle? Y-valves provide some redundancy if you forego a pony bottle, but with a pony bottle they seem superfluous. That is the exact valve i am trying to sell. I think I have three of them.

 

[kr2y5]

I'm looking for other divers opinion about a possible equipment purchase.. I would appreciate pros and cons from divers who have done the diving with equipment described. Here's my background:

Closing on 50 years old, been diving about 4 years and have about 300 dives, all freshwater (Great Lakes and Quarries)? I love the shipwrecks. I may want to get into saltwater when my kids are gone and I have more time and money. Same with cave training. That won't happen for awhile either.

Certifications: OW, AOW, Deep, SAR, Drysuit, Rescue, and Solo

I would like to do some limited wreck penetration mostly at rec depths but maybe as deep as 150 so I need some technical/decompression.

Money/value/safety are all considerations:

1. Y valve with big steel tank 149cuft? Could I use my existing Knighthawk and Drysuit ? All I'd need would be the cylinder.

2. Doubles with BPW. I would need to purchase all of this.

3. Side mount. Need to purchase all of this.

Is there any configuration that would allow me the flexibility to switch between these.

Ok Divers, help me out give me the pros and cons. Thanks for all your help.

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I would not venture into any sort of technical diving without doubles, whether backmount or sidemount... I am sure some can pull that off with Y valves, ponies, and other arrangements, but IMHO, it all seems like awfully complex ways to address a problem that is most elegantly solved by carrying a pair of identical tanks. If money is a concern, I would also not start with sidemount. Since it is less standardized, and by its nature, it involves experimentation, there's also a higher chance that something won't work for you, and you will end up spending more money in the search for the right setup. With the backmounted doubles, you can just go with one of the standardized configurations (GUE, or whatever), and I'd think your satisfaction is guaranteed... no need to take responsibility for making what could turn out to be expensive decisions on your own. With a pair of HP100s, one can do comfortable rec dives, and plenty of light technical stuff... I've even read some people argue somewhat convincingly that they're the most optimal setup for most Tech 1 level dives. I don't own a tank bigger than HP100. If I were to need more gas, I'd seriously think of using a bottom stage, before deciding to put more heavy steel on my back. HP100s are just about right. The only reason I would consider sidemount instead is if you find it physically challenging (or expect to find it challenging) to carry doubles, or to reach your valves. Sidemount would be easier...

 

[CamG]

Hello Mick my advice is going to be pretty simple.
If I were you just pondering getting into deeper longer dives, I would look for a Tech diver who has a BPW and a set of 85's doubled up.
Used BPW and doubles are out there especially with so many going to SM right now.
I have done both BM and SM, currently Im SM as it works better for me personally.
I do dive off boats and it can be different but conditions can make both SM and BM difficult at times.

Used or new up to you but if you stick with 85's they are extremely versatile.
LP 108's are 8 inch tanks, swim a lot like 85's.
Ive BM both and have two sets each that I SM now.
I would enlist the help of a instructor that you desire to train with.

I would not suggest a Y or H valve seemed a waist to me when I was in your spot.
You will enjoy the gear and training with a great instructor, which I know of a few in your area will be a blast.
PM me if you want any names or if you are looking for used gear I have a few buddies selling right now.

CamG

 

[RJP]

I think handing your cylinders up before climbing the ladder would be easier in sidemount.

Speaking as someone who has crewed on a boat for many years... It's much easier if the divers haul their own s**t of the water.



But seriously, divers handing stuff up is a pain in the ass for the diver doing it as well as the other divers waiting to get out of the water. Multiply that by eleventy if the water is anything but dead calm.

Sidemount divers also do a number on fiberglass decking. It's called a GIANT stride for a reason folks...