Been reading this thread.... it strikes me that the OP has a listed total of 0-24 dives, and self-admits not knowing how to calculate detailed air consumption, has a high consumption rate, and the solution is to just carry 130 cf and a pony. Add in task saturation with spearfishing, and we're talking a potential for some potential risk here. Not telling anyone how to dive, but rather suggest to tread lightly! I'd think that spearfishing at 130' fsw is prime for some EANX discussion.
Hello RVbuilder,
I concur with your assessment.
May we use the correct nomenclature for the term "pony bottle" as it relates to the OP's description for his planned actions? The OP is using his second rig not as redundant gear, but as as a stage bottle. A stage bottle to be used when he sucks his primary system "dry". Where is his redundant gear? Is he following the rule of thirds? He is talking about using technical diving tactics with seemingly no competent knowledge of technical diving protocols.
I do deep stops while recreational diving all the time. The format I am following is multi-level diving. However, I don't think the OP is planning on using half, or some other portion thereof, of his NDL time at 130 fsw and then ascending to 85 fsw for a typical multi-level dive format.
Disclaimer: I don't go to 130' and then burn-up my entire NDL and plan on doing deep stops up to the surface. When my computer's NDL graph is flashing yellow, with staged decompression on the so-called horizon, I forget deep stops,
or multi-level diving, and safely ascend to the surface (by following NDL protocols which includes an optional safety stop).
OP: Diving to 60' is relatively benign. CESAs, if performed properly can save your life and you may avoid serious injury (in many cases [caveat emptor]). A speedy ascent from 60' while constantly inhaling and exhaling gas is quite survivable. At 130 feet, and deeper, real SCUBA diving begins. Compound issues and mistakes can turn fatal. And quickly.
Please, get more experience and training from a competent technical diving instructor before doing what you are planning.
thanks,
markm