there are some with a "soft" backpack, see above. but you'll need two cambands for them.
My setup is also optimized for weight, although not as radically as yours.
It is a DSS Kydex plate, their 30lbs LCD wing, hog harness with all stainless hardware, and a "custom" integrated weight system consisting of 6 weight pockest and some additional webbing. It weighs in at 7.8lbs.
I am guessing that this could roughly be cut in half by:
- using plastic buckle and d-rings/stopper instead SS
- use a smaller lighter wiing, e.g.
https://www.deepseasupply.com/index.php?product=120
- eliminate 1 camband (no problem with a stiff plate)
- eliminate/reduce weight integration
What I always find a nuisance when packing small is the stiff webbing.
For the limited application as you described, I suggest to consider the more plyable, softer 2" webbing often used for crotch straps. Also lighter weight.
Above approach would not quite get you to 2-3lbs, but has the beauty that you get a setup that can be easily re-configured for "regular" diving, i.e., more economical.
I find another great weight saver are fins: most people insist that only open heel fins are for "real" diving. However, I found for my purposes full foot fins are just as good and weigh in at less than 50%, also cheaper. Unless you need thick expsoure protection/boots, good way to go.
Let us know what you came up with.
