A single tank with an H-valve still isn't truly redundant; if your tank o-ring blows, you're in a world of hurt. A lot of us feel that it really isn't ideal to be in an overhead environment without complete redundancy -- in addition, if you intend to go further in training, you WILL need a redundant setup, so why not obtain one and become facile with it, before getting into the overhead?
Cavern is a great class to learn non-silting propulsion, and to refine buoyancy skills. It is my personal opinion that there are better options, if that is what you want -- options you can pursue in an open water setting. If you are truly interested in diving caves, why not prepare yourself properly for doing that? Get a set of doubles, and work with them in an open water environment until you are comfortable with them. You can take a Fundamentals or Intro to Tech class, and even add an overhead protocols class, and go into your cave training well ahead of the curve.
Rushing into the caves in what amounts to tweaked open water gear may be fine if you don't want to dive caves, and just want some skills refinement . . . but if your goal is to cave dive, prepare yourself for cave diving. Do everything you can in your available open water environments, and spend your cave training learning what you have to learn IN a cave.
I don't know anything about 119s and how they are doubled up, but some tanks work far better than others. If you have any opportunity to do so, I'd borrow as many different sets of tanks as you can, to see what works for you. I started out in LP72s, because I thought they'd be easy to carry. And they were, but I couldn't trim the danged things out to save my soul. The first time I dove my LP85s, I thought I'd died and gone to heaven. It's not good to spend the money to buy tanks, only to discover that you can't ever be really comfortable in them (which, I think, is why so many sets of 95s go up for sale . . . )
Cavern is a great class to learn non-silting propulsion, and to refine buoyancy skills. It is my personal opinion that there are better options, if that is what you want -- options you can pursue in an open water setting. If you are truly interested in diving caves, why not prepare yourself properly for doing that? Get a set of doubles, and work with them in an open water environment until you are comfortable with them. You can take a Fundamentals or Intro to Tech class, and even add an overhead protocols class, and go into your cave training well ahead of the curve.
Rushing into the caves in what amounts to tweaked open water gear may be fine if you don't want to dive caves, and just want some skills refinement . . . but if your goal is to cave dive, prepare yourself for cave diving. Do everything you can in your available open water environments, and spend your cave training learning what you have to learn IN a cave.
I don't know anything about 119s and how they are doubled up, but some tanks work far better than others. If you have any opportunity to do so, I'd borrow as many different sets of tanks as you can, to see what works for you. I started out in LP72s, because I thought they'd be easy to carry. And they were, but I couldn't trim the danged things out to save my soul. The first time I dove my LP85s, I thought I'd died and gone to heaven. It's not good to spend the money to buy tanks, only to discover that you can't ever be really comfortable in them (which, I think, is why so many sets of 95s go up for sale . . . )
