Imported post
1. They are too bulky
They're bulky, true, but whether they're "too bulky" or not is surely a personal thing..
2. The valve can be opened slightly, or can leak whilst stowed, leading to a potential uncontrolled ascent
Absolute myth. When it's rolled up and secured, the valve will dump the air, and the only thing that happens is you get bubbles and an empty bottle. An uncontrolled ascent will NOT happen. Try it if you don't believe it.
3. People often *forget* to fill them
True, but that's their fault, not the product's. I haven't forgotten so far.
4. The small cylinders are exempt from routine tests, leading to neglect and potential failure.
Potentially true, but nothing stops you exchanging it for a new one periodically anyway, and you're encouraged to do so by the manufacturer.
5. Cracking the valve and *letting go* produces far too much lift, leading to a potential uncontrolled ascent if a reel should jam.
Not true. You can open the bottle as much or little as you like - if you only
just crack it, it can inflate SLOWER than a half-filled SMB expanding as it goes up.
6. They're expensive!
Sad, but true.. but so is Halcyon
A closed lift bag/SMB can be inflated mid-water, at depth or on the surface
So can a crack-bottle SMB, and without all that frigging around with connecting and disconnecting hoses...