PST (Pressed Steel)HP120s VS New PST E7-120 & E8-119

[Doc Intrepid]

fools rush in.

Oharag, the situation with new divers is that they don't know what they don't know. Even with your OW and AOW certs.

It occurs frequently enough here that its almost a cliche to hear a brand new diver proclaim they're going to buy a set of doubles and do the Doria. You are not unique.

What people are trying to suggest is that UW proficiency derives from experience, particularly experience when things go wrong. When you buy your doubles, go deep, and stay long, there is far more opportunities for things to go wrong and far less room for error in your response. This is why statistically the majority of diver deaths occur to less experienced divers (DAN, 2001). You would be more prudent to spend your money on training and your time pursuing recreational diving for a year or so, before adding additional task-loading to your profiles.

And fill out your profile, so the rest of us can put your remarks into some sort of context.

Doc

 

[Scuba_Vixen]

The best advice, when it comes from a woman, often goes unheard by the men who need to hear it most......

Glad it wasn't just a blonde moment,

Darlene

 

[japan-diver]

Have to agree, the shop wants to sell you the double set-up as its quite a large purchase but rushing in to doubles isn't the best idea. Master a single, get the air consumption down then think about moving on. Do you already have the BC/backplate to handle doubles, how about two quality regualtors

There is much more to diving doubles to jumping in the water and breathing. The nitrox and dry suit are also good things to start at this point but try adding on new thing at a time and slow down in this sport those who try to rush experience end up dead.

 

[Genesis]

trim and swim VERY differently than singles.

I'm starting to work with doubles now, and my buoyancy and trim is NAILED spot-on with a single.

Well, with doubles its just a "bit" different

If I had tried to start diving doubles immediately out of OW, I would have been thrashing around like a turtle on my back - that would not have been fun.

I agree with the others - get 50-100 dives under your belt before considering it, and make sure your trim and buoyancy is NAILED before you attempt this. Also note that you will need a backplate and wing designed for doubles in order to safely use them, and that out of the water they are a BEAST to move around!

The "golden rule" for progressing safely in this sport seems to be to make one change at a time - and no more. So in this case, if you want to dive dry with doubles, and currently dive wet, you need to first get the appropriate BC setup (backplate and wing) for it, dive that with a single (you'll need a wing designed for singles), then I'd learn how to dive the drysuit, and THEN I'd add the doubles, and only move to the next step when you're COMPLETELY comfortable with the last.

 

[RiverRat]

E7-100s... are what I'm going to double.

More than enough for me to have the redundancy for one mandatory-deco dive, and if nothing goes wrong, I can do a second non-deco dive on the same gas.

Within nitrox-diveable limits this is a very workable combination. It perhaps won't work as well for Trimix diving if you have a truly extreme exposure, but for those of us diving in the 130'ish range on custom Nitrox mixes, and who are using deco as a means to get more time (rather than to go deep and get a reasonable time on Trimix) its a definite reasonable option.

Hey Genesis, I know this is an older thread and about doubles, but I'm thinking of getting a PST E7-100 for local diving with a single. With all the neoprene we use up here and the fact I'll probably start diving dry in the near future it makes sense. After looking at the PST tank chart I wonder if I should go with an E7-120 or an E8-119? The E8-119's buoyancy characteristics when full are actually closer to the E7-100 than the E7-120. The E8-119 is the same length as the E7-100 but fatter and heavier dry than both of the others. I'm still new and have no intention of diving doubles anytime soon, but maybe sometime in the future. Any thoughts?

 

[Genesis]

Hey Genesis, I know this is an older thread and about doubles, but I'm thinking of getting a PST E7-100 for local diving with a single. With all the neoprene we use up here and the fact I'll probably start diving dry in the near future it makes sense. After looking at the PST tank chart I wonder if I should go with an E7-120 or an E8-119? The E8-119's buoyancy characteristics when full are actually closer to the E7-100 than the E7-120. The E8-119 is the same length as the E7-100 but fatter and heavier dry than both of the others. I'm still new and have no intention of diving doubles anytime soon, but maybe sometime in the future. Any thoughts?

Yes.

If you dive from commercial boats, the E8s will give some boat operators fits, as they are all set up for the 7.25" size of the E7s/AL80s.

The E7-100 is a fantastic tank for most divers. The E7-120 is a good tank IF you are relatively tall (6' or so); if you're short it sucks, as its too long.

I own both E7-100s and an E7-120 and use 'em both. The E7-100s are doubled right now and I may break them down, as they kinda bite doubled (head-heavy; I can deal but its not really all that wonderful); I may get a second E7-120 and double THEM instead.

 

[RiverRat]

Yes.

If you dive from commercial boats, the E8s will give some boat operators fits, as they are all set up for the 7.25" size of the E7s/AL80s.

The E7-100 is a fantastic tank for most divers. The E7-120 is a good tank IF you are relatively tall (6' or so); if you're short it sucks, as its too long.

I own both E7-100s and an E7-120 and use 'em both. The E7-100s are doubled right now and I may break them down, as they kinda bite doubled (head-heavy; I can deal but its not really all that wonderful); I may get a second E7-120 and double THEM instead.

Thanks Genesis! Good point on the E8 size. Of course that might keep overly helpfull DM's from jamming my new wing between tanks like on my last trip
And I too was concerned that the short E7-100 might blow my trim. The 120 may be the way to go as I'm 5' 10", may make a good fit.
decisions...decisions.........

 

[Genesis]

And I too was concerned that the short E7-100 might blow my trim. The 120 may be the way to go as I'm 5' 10", may make a good fit.
decisions...decisions.........

A SINGLE E7-100 will not blow your trim. They're gorgeous tanks dove as singles - I love mine in that application.

They do, however, take some care (and the right wing!) to use successfully as doubles.

I've found that with the Abyss 55 wing, AND a drysuit, AND the weight that I need with it on a W&T harness (so I can get it at approximately hip level) they balance ok. In a wetsuit with an AL plate (to keep the weight down) I'm head-heavy and quite uncomfortable with double HP100s.

I don't know if the 120 will do the same thing, but logic says it SHOULD NOT, since its much longer.

 

[Warren_L]

Yes.

If you dive from commercial boats, the E8s will give some boat operators fits, as they are all set up for the 7.25" size of the E7s/AL80s.

The E7-100 is a fantastic tank for most divers. The E7-120 is a good tank IF you are relatively tall (6' or so); if you're short it sucks, as its too long.

I duuno about the 6' thing. I'm almost 5'9" and love my E7-120s. Haven't doubled them up yet, but may try it out sometime soon.

 

[GDI]

I have a pair of single PST (Pressed Steel) HP 120s I am considering using as doubles. Does anyone think there would be any advantage to trading them in for the new PST E7-120s or E8-119s...and if so which ones?

I got them new last Fall, dove them once and then for logistic reasons (Military) have been separated from them. I know the new E-series has the more common 3/4-14 neck thread as opposed to the HPs 7/8-16 neck which might (?) be preferable for doubles. Also, the new NRX valve for dual outlet capability sounds kind of interesting.

I am about 6'3", 215-220#, dive dry 85% of the time...mostly open water/wrecks. I am starting to get into more technical diving.

I really appreciate the help, thanks!

Semper Fi,
MudDog

I have both a e series 120 and hp 120's. Either set makes great doubles. You will notice some slight buoyancy characteristics but nothing major. You can also get manifolds for the Hp from DR, seaelite, genesis
and there are some others.