I wear mine when fishing in rough or cold water just because I am not as nimble, or steady as I use to be, and am not depending as much on the auto unit, but my own hands to pull the inflation handle, this is the same reason that I added an E-ladder. But I always wear my good old bulky red Bass Cat Stearns vest when high speed running. But the first thing I did when I bought my inflatable was to actually test the vest at the local boat launch, and the original HIT valve and Co2 cartrige worked flawlessly, after repacking and re-arming I hope the new one works as well. Working like I do in the Oilfield, I believe every boater should take a water survival course at least once in their life (our company requires it every 2 years), or at least try getting back in their boat their selves (but with friends around just in case) from in the water a few times, so that they can see how difficult it can be when your fully clothed, especially in cold water or heavy seas or current.