Optimal SM tanks bigger than 100s

[Brojas]

Hi all,

I am 5’11 and am currently diving a Dive Rite Nomad LS and Worthington HP100s. Im currently deciding between just getting a another set of 100s or sizing up to 85s, 95s or something bigger and don’t know which way to go. I’ve heard certain tanks have buoyancy characteristics that may require me to adjust bungee length. I’d like to avoid this if possible. Does anyone know what tanks would pair well together?

These tanks would be used for sidemount only. I’m only apprentice cave at the moment, so bringing a stage is not an option until after full is signed off on (have to polish up on my feathering and other no viz skills)

 

[lostsheep]

Sizing UP to 85s or 95s from 100s?

I assume you’re getting cave fills?

 

[Brojas]

Sizing UP to 85s or 95s from 100s?

I assume you’re getting cave fills?

Yes, 35-3600 most likely. Good callout.

 

[tbone1004]

your worthington HP100's are bricks compared to any other HP100, they are very negative around 3.5lbs when empty. Any other tank except an LP104 will be about 0-1.5lbs negative so there will be changes to your current rigging. The top bungee won't change, but the bottom will. I would go to LP85's which will get you a bit more gas without all of the extra weight. HP120's may be a skidge too long but will at least be closer in buoyancy to your 100's

 

[Brojas]

Thanks, @tbone1004 for the reply. I don’t mind the extra weight of the worthy 100s, as I’m still working on relaxing my breathing (especially after fighting the flow). I actually have a set of Faber HDG Hp120s, but they are relegated to single tank rec diving due how annoying it is for the tanks to tap my thighs in SM. Maybe it’s a skills thing.

I suppose there has to be a reason why so many people use 85s. Now, if only I can find some PST or Worthington 85s…

 

[Marie13]

@Brojas

What’s wrong with Faber 85s? Just curious.

My 85s tap against my thighs, but I’m also 6” shorter than you. You just get used to it.

 

[Brojas]

@Brojas

What’s wrong with Faber 85s? Just curious.

There’s nothing wrong with Fabers, obviously. I’m actually really tempted to just break down and get some HDG 85’s now that they are starting to get them in again. I’ve just come to enjoy the extra weight at the end of the dive. I’m sure when I relax a bit more, I won’t need it.

 

[tbone1004]

Thanks, @tbone1004 for the reply. I don’t mind the extra weight of the worthy 100s, as I’m still working on relaxing my breathing (especially after fighting the flow). I actually have a set of Faber HDG Hp120s, but they are relegated to single tank rec diving due how annoying it is for the tanks to tap my thighs in SM. Maybe it’s a skills thing.

I suppose there has to be a reason why so many people use 85s. Now, if only I can find some PST or Worthington 85s…

you are a bit on the short side for 120's, but they're all going to tap at your sides if you are diving them properly.... They shouldn't be butt high. Can you post a picture if you in the water with the Worthingtons?

 

[Brojas]

Can you post a picture if you in the water with the Worthingtons?

I actually don’t have any in water pics with them. I’ll message my instructor and see if he has some old pics from a video review. IIRC the ends of the tanks are 2-3” below my waistline

 

[mdwalter]

Hi all,

I am 5’11 and am currently diving a Dive Rite Nomad LS and Worthington HP100s. Im currently deciding between just getting a another set of 100s or sizing up to 85s, 95s or something bigger and don’t know which way to go. I’ve heard certain tanks have buoyancy characteristics that may require me to adjust bungee length. I’d like to avoid this if possible. Does anyone know what tanks would pair well together?

These tanks would be used for sidemount only. I’m only apprentice cave at the moment, so bringing a stage is not an option until after full is signed off on (have to polish up on my feathering and other no viz skills)

I'm about your height, and I find LP85s to be the right tank for the job. I tried 95s, but they felt almost "too short" especially for how fat they are. I tried LP 108s once, too. Those are not too short, but they are still 8" fat so still annoying and more volume than I feel like I really need. Honestly, I feel the same about these tank sizes for back mount too, but for slightly different reasons. In either configuration, the 85s are more streamline, seem to be the right length to trim out well and not hit me in the wrong spots, and hold almost the same amount of gas as the fatter tanks.
If your only concern is gas volume, however, here's a quick comparison of how much each tank you are considering (and a few more) holds at 3600psi
HP100 - 104cf
HP120 - 125cf
Steel72 - 115cf (if you dare to overfill by 60% over rated working pressure)
LP85 - 116cf
LP95 - 129cf
LP108 - 147cf
LP120 - 164cf