Final answer:
A life jacket should be discarded and replaced if it shows any signs of wear and tear, damage, or if it no longer fits properly.
Step-by-step explanation:
A life jacket should be discarded and replaced if it shows any signs of wear and tear, damage, or if it no longer fits properly. Signs of wear and tear can include fading, fraying, or broken straps, while damage can include tears or holes in the material. It is important to replace a life jacket that no longer fits properly because a proper fit is necessary to ensure it can function effectively in an emergency. For example, if a life jacket is too loose, it may not keep a person's head above water.