Originally Posted by Bob & Mag

I've often asked this question as it seems there are always plenty of expired ones around. One important thing is DON'T store them with your new ones as it's a no-no but I do carry an old set on the boat seperately.
One thing you can do with the extras is donate the to an Aux. Coast Guard station to be used in one of their training classes.
Eventually you'll have bunches of them. Another thing I've noticed is when buying them, check the stock on the shelf as I've seen quite a variation in expiration dates(as much as a year).