Larger Tanks for deep dives (100ft)

[H2O 70]

use the hp 100, sling an al80

Just curious, but why do you suggest this?

As pony tank is there for a worst case scenario. It is a bail out tank. It isn't part of the gas plan. Well, shouldn't be part of the gas plan.

So the HP100 isn't going to help out with his need/want/desire for more back gas and slinging an AL80 is a big tank to sling. He is carrying 2/3 of his back gas in a pony?

 

[svs]

It depends of how much air you have left by the time you hit NDL. If you still have around 1000, you don’t need another tank. Pony though will be still helpful for other reasons. Minimal size depends of the amount of air you need to ascent safely from say 130ft.

 

[FireInMyBones]

I love my HP 120. Buying double 130s this fall. I sling a 40.

 

[fnfalman]

I like my Faber HP120 M-series. Same buoyancy characteristics as my Faber HP100 M-series but more gas.

 

[Meng_Tze]

I vote for more shallow diving till you are better with your gas consumption.

To add to that. You should know/be able to assess what tank you would want. How deep, how long, what profile, what reserves. Combine this with consumption, you should get an idea of what to carry.

 

[ianr33]

To add to that. You should know/be able to assess what tank you would want. How deep, how long, what profile, what reserves. Combine this with consumption, you should get an idea of what to carry.

Also bear in mind you need to figure your higher than normal consumption rate when calculating gas reserves for a buddy team.

Not much use you having a huge tank if it has just freeflowed and emptied. If your buddy in that situation is a tiny girl using an Al 63 then you could both be in a world of hurt.

 

[UCFKnightDiver]

Just curious, but why do you suggest this?

As pony tank is there for a worst case scenario. It is a bail out tank. It isn't part of the gas plan. Well, shouldn't be part of the gas plan.

So the HP100 isn't going to help out with his need/want/desire for more back gas and slinging an AL80 is a big tank to sling. He is carrying 2/3 of his back gas in a pony?

Who said anything about a pony?

 

[H2O 70]

Who said anything about a pony?

Actually the OP did.

I am also looking to carry a pony on a pony bracket attachment. What size would
you need with a 118?

 

[Puffer Fish]

I'm your size and have Faber 100's, 117's and 133's....my default tank for deeper diving is the 117's...

Comparing Worthington versus Faber FX series... some sizes favor Worthington, and some Faber, the 117 weights in at 3 lbs less...and gear weight can add up.

There is the thinner 120's..which fit easier in boat racks, but are really tall, and much harder to find sales on...

I have a fairly low SAC rate (typically between .4 and .5cf/min) for a big guy and even matching up nitrox with the depth, normally come back at near the NDL limits with around 1,500 psi in my tank. I would think it would work reasonably well.

What about doubles.. well you have the cost, the cost of filling and the pain of dragging the things around..when I taught at a shop... I used doubles...now I like the lower weight, and ease of transport.

Pony... well the lightest reasonable tank is a 20 (have one)... but it is easy to make an arguement for bigger (depending on it's use), so a 30 (have one) or a 40 could be done. If you only have one, would suggest the middle path and get a 30. There is no reasonable no-deco or short deco that one cannot do with a 30...and both the size and weight are reasonable.

 

[Sas]

I dream with an HP130.
There is no rental steel tanks, only those AL80.

Locally to me they pretty much only rent steel (HP100s) unless you specifically request otherwise.

I use a HP100. That tank lasts til NDL with air or nitrox diving down to 30m. But if you have high air consumption just get something bigger than that, but that is still comfortable to dive with and cart around.

To calculate what pony size you need, work out your SAC and your stressed SAC and see how many litres you would need to get to the surface in an emergency. Get a pony that holds that amount (or more ). I am not sure how the mounting system works but you can always sling a pony.

Re doubles, they are a lot of expense and there are other issues to consider with them. If you are not going to dive deeper than 30m I am sure a single + a pony is suitable.