How often should they be replaced? With age, I figure they would eventually rot. Instructions say to test every season before use, which I would do by jumping in swimming pool during vacation. And replace the cartridge. I keep it stored in closet.
You can always manually air them up to make sure they still hold air just to be more comfortable.Great question, I'm the team lead of our oil spill response team out at the plant I work at and reached out to a manufacturer of the PFDs we use and they basically said they didn't have a recommend replacement date. Just do you inspection each time you get ready to use it and replace when showing signs of wear. Hope this helps