So I'll be going for my Advanced Certification in the next 3 weeks or so
However the nature of the depths does have me on the cautious side of things. I have been considering buying a pony bottle. I've seen quite a few people with them and just to know if something were to happen to my regulator setup or by whatever means I mis calculate my air left for ascent it would be nice to know I can salvage a few more breathes.
So what is the overall thought on these? Worth the price or just be extra cautious and play it safe?