Time Out was a series of PSA's produced by NBC Sports (!) during the 1979-80 season. I at first thought these were used on Saturday mornings, and maybe they were, but these seem to have been more prevalent during, of course, sports programming.
With summer a couple of months away, Kim Richards, at the time appearing on Hello, Larry, helps explain what a lifeguard does.
The poster on YouTube got the date wrong, as the copyright, albeit somewhat fuzzy, shows this is from 1980.
I don't know how many of these were made, but they are hard to find.