PST E7-120s and E8-130s...

[MacLeod]

I would really appreciate member's help...I have been really struggling for over a year trying to decide between the PST E8-130s and E7-120s. I am looking to buy 2 to dive as singles for the time being. I am 6'4" and 220lbs. I dive everything from lakes and quarries to the St. Lawrence and occasionally the Atlantic (Jersey Shore, Rhode Island, NC and Florida). I generally dive dry (except FL and some shallower warmer/summer dives).

I know most of the tech guys love the 130s (especially the DIRs)...apart from the extra air, they claim it has better buoyancy characteristics (and remains 1 pound negative when empty (as opposed to the 120s neutral when empty).

On the other hand, several of the local dive shops have looked at me like I was nuts when I even mentioned the 130s. They claim the 120s are:
"what everyone uses for Jersey diving...why would you ever want a 130? They won't even fit the dive boat's tank holders. Besides, with (my) height, you want longer tanks."

Several years ago I made a couple of dives with the old PST HP 120s. They were nice, but actually seemed a little long at the time (I remember I kept hitting the back of my head on the valve...probably more of a rigging situation that I could have altered if it were going to be more permanent.

Would the wider E8 8" diameter tanks make one more turtle like (back heavy) than the 7.25 inch E7s? Is there really any greater "performance" with the E8-130s?

Bottom line, I would be really grateful to hear what people think would be the advantages of each tank (other than 10 cuft of air ).

Thank you VERY much!

 

[Hoosier]

Hmmm~

Simple question at first:

Do your LDS~s have E8-130 tanks in stock when they talked with you?

 

[MacLeod]

Hmmm~

Simple question at first:

Do your LDS~s have E8-130 tanks in stock when they talked with you?

Hi Hoosier...no, they did not have either the 130s or 120s...they would have had to order either one.

 

[ScubaDadMiami]

I can't comment directly about the 130s since I have never used them. I have E-7 120s doubled up for almost two years now. Before that, I was using 8 inch, steel 95 low pressure tanks.

First, the 120s are lighter out of the water. This matters a lot to me when having to climb out of the water.

Second, I know it would seem that 3/4 inch would not be a big deal, but I swear I can feel a difference in how much effort it takes to move through the water. I think these are very streamlined compared to the low pressure tanks.

Disadvantages: I am only 5'8". So, I need to use a boat seat cushion, an investment of about 10 bucks, to sit on while on the dive boat bench seat.

Second, these tanks tend to orient a lot of people too far in a head down position. It took a while of adjusting my gear to get the balance right. However, now that I have things like I need them, these are sweet tanks.

I really wouldn't sweat the difference between the one pound negative versus neutral when empty issue.

Hope this helps.

 

[large_diver]

Who cares what the guy at the LDS says....buy what works for you. To me, if I am going to lay down ~$400 for a tank, I want the extra 10 CF.

I guess the tank rack issue could be real....but you can weigh that against the boats you usually use.

I am 6'5" and 245. I have an LP 104 and have an E8 130 on order to replace an old OMS 98 (the 104 and the 130 are pretty much the same tank in terms of dimensions and buoyancy characteristics). I've had the 104 for about 4 years and enjoy it. Turtling -- I've never found this to be a big issue. Trim under water.....again, I am able to consistently maintain good horizontal trim with this tank (drysuit....no gaiters...no ankle weights and I wear my tank pretty high - I can touch my reg with the back of my head..arch that back)

Anyway, hope this helps.

-Chris

 

[Hoosier]

OK,



There are two big concerns, weight and compatibility, on your option.



Weight:

As long as you can handle the tank weight, it isn’t an issue. I am not a big person compared to you, but I also have E-130. I think that twin E-130s is going to hurt me, but other member was teasing me to exercise for that. I took the point to be more energetic for both twin setup and my GF. E-130 is 5 lb more and 2 inch shorter than 120. [http://www.diveriteexpress.com/gas/steel.shtml] The height was the main concern to me. The 5 lb difference in the tank weight is out of issue in underwater.



Regarding the neutral buoyancy with the empty tank, no matter what kind of tank you have, you need to have the extra weight. So, it doesn’t matter.



Compatibility:

It can be your main concerns depending on where you are diving mostly. If there is no rack for 8 inch tank, it would be your hassle. So, it is your call….



My 2 cents.

 

[bcsean]

I'm 6'-3" and decided to go with the 120's for the trim charcterisitics. I wanted a longer tank for the exact reason of keeping the valves up near my head. The bands are only about 3/8" down from the crown, so the valves are gonna be in teh same spot regardless of tanks most likely. Not a big deal. Get a din reg and it pulls the reg in better anyway.

If I was to do it again, I'd still go 120's.

 

[hex92]

120s are the way to go.. I have 2 120s that I use as singles and they are frickin awesome. Worth every penny. I don't know why I bought a set of dbl 95s this year....Oh yeah now I remember I did it cause I can't stop spending $$ on gear and they were only $730 for the set. I made a block of wood to set the 95s on so I can get my gear on easier.

The 120s are great for single tank dives I may end up doubling them up eventually too.

I'm 6'4" 200 lbs

 

[triton94949]

Hmmm~

Simple question at first:

Do your LDS~s have E8-130 tanks in stock when they talked with you?

I ordered mine. It took them 4 months to get here. So don't hold your breath. Hoosier is right.

I think however you are mixing apples and oranges. Your singles will not make good doubles. Your singles are what you will be using for NDL scuba. That is totally different from what your doubles will do. Choosing one based on the other makes no sense, as you will see, when you finally have doubles.

 

[MacLeod]

Thank you everyone for your replies...I really appreciate you taking the time to help me with this decision!

In previous articles and posts I have read, it seemed people preferred 130s. Here, however, from what I have seen people seem fairly evenly split in their preference. Hoosier, Large_Diver and,triton94949 you seem very happy with your 130s (although Hoosier you do mention the weight is a concern particularly in terms of any thoughts of future doubling).

ScubaDadMiami and bcsean you speak out strongly in favor of the 120s. Bcsean, as you mention, the valves should wind-up in pretty much the same location for both the 130s and the 120s with the main difference being how far down the base of the tank comes in relation to ones lower back/butt. This would of course be different if the tanks were particularly short (in relation to ones height) and trim necesitated moving the tanks lower down your back (making the valves lower). This would be less than ideal of course bkz then one could not reach back easily to get to the valve.

I guess ultimately I am wondering, what would make the 130 or 120 a better choice over the other assuming both "fit" the diver (neither too long or short in terms of valves and trim previously discussed). Seeing as both are pretty close in weight when empty (only a 1 pound difference when empty (130=-1; 120=0), what makes one a favorite over the other?

130:
shorter (26.12")
wider (8")
10cuft MORE air
5# heavier (43#)

120:
longer by 2.13" (28.25")
Thinner (7.25")
10 cuft LESS air
5# lighter (38#)

BOTH bouyancy = -10.5# full (according to PST chart).

Hmmm...5 ponds does not seem like it would be that much difference in weight (yes?)...but would the fact that it (130) is shorter or wider make it "perform" better or worse than the 120 which of course is slightly longer and "thinner"?
I am still at a loss...