Help with which pony?

[redacted]

A 6 is probably pushing it if you are planning to do a normal ascent. But as an aide to a faster (CESA type) ascent it should work fine. A 13 is OK but can get close to the edge if used deep and is a bit off of full. The nice thing about a 13 is it will pack OK for air travel. If air travel is not a consideration, then the 19 is great as the burden is about the same as a 13 but you have plenty of air even if the pressure gets down to 2500.

 

[RDRINK25]

Again I am looking for my wife. The 13 would be used with me on dives 60-70' and with her on dives around 100. She is 5' and 120lbs and has a great air consumption. We always dive together and I would notice her bolting to the surface would you not think I would be right behind her. With my tank at the saftey stop we can buddy breathe at that point. Just was my thoughts please chime in if I am thinking wrong here. The 6 would be for her on dives to 60' while I am using the 13. I already own a 30cf for my deep dives.

 

[Hatul]

My rule is 19 for dives deeper than 60 ft and 13 for dives 60 ft or less. That way you have enough to make a safe controlled ascent with safety stop, and knowing that has a psychological benefit, which is important as anxiety hurts and panic kills. However in most cases of failure that you can conceive, you should be able to make it up to 60 feet with the main tank and then you can switch to a 13 to make the final ascent.

 

[flots am]

It's not difficult to calculate if you know your stressed RMV and your maximum planned depth.

For a 2.0 CFM stressed RMV, an 80' dive, 1 minute to look around and get your act together, a 30'/minute ascent, and a 3 minute safety stop, a 30 CuFt tank is just about enough.

If you're really freaked out, or you're going deeper than 80', 30 CuFt isn't enough.

If you have different numbers, I'd be happy to run them for you.

flots.

 

[tamas970]

I just decided for a 4L 200bar (29CuFt) steel tank. I have to see if its too big or heavy, never had a pony before...Originally I wanted more, but 40CuFt is heavier & bulkier.