It's there a "pocket-sized" buoyancy aid that locks into a small canister you can strap to your wrist/ankle? I'd guess not due to insurance liabilities.
Yes, yes there is. It straps to your wrist and uses a CO2 canister like the ones used to inflate bicycle tyres: https://www.amazon.com/Kingii-Lightweight-Wearable-Portable-...
It's there a "pocket-sized" buoyancy aid that locks into a small canister you can strap to your wrist/ankle? I'd guess not due to insurance liabilities.