Interesting, but an important test would be how long the cheapo life vest held air I.e. kept you afloat. It would take rescuers a while to get to you 20 nm offshore. You can test this by inflating the vest firm (by mouth) and checking on it hourly. See how many hours it holds air. The standard is at least 2 hours.
You need to replace the cartridges about every other year. Since you didn’t do much research before buying. Maybe you missed that you need to maintain that thing every year. The water sensitive cartridge has a date code on it, and should be replaced when the date has past. This is due to moisture build up. The CO2 cartridge, should be weighted on a scale every year. They might loose CO2. Weight should be printed on cartridge. A good way that boat people do remember to test these things is: Either in start of boat season, or at end of boat season every year. You take a jump into the water. Then you replace both cartridges and repack the life jacket.
Well of course do your research first. A lot of jackets don't come with Co2 cannisters because they can go out of date. I might also add that a crotch strap is a useful addition because it's possible that the jacket could slip off over your head making it next to useless. Finally, relying on a pull cord activation isn't always the best solution because it's possible you could get knocked out or disorientated and then can't inflate but this is perhaps more important for us boaters.
@richardstamper5630 Yes, I agree that for a boat, automatic inflation is a great idea, and just for that reason. should you be knocked out ot can get to the cord, it will inflate for you. For aircraft use, you want to be able to swin a safe distance away before inflating to prevent getting trapped inside.
