In Memphis, our long time FM AC station, WRVR played pretty much all the songs on Sirius Yacht Rock channel from the time they were new until about 20 years ago. Seemed like when I traveled, most AC stations sounded like WRVR did in the 80s and 90s.
I was talking to a guy born in 1982 about yacht rock at a Labor Day party and he knew all those songs because when he was a kid in the 1990s, his mom always had on The River in the car.
So I would argue that most of the Yacht Rock playlist was still widely heard for a good 25 years, until the early to mid 00s.
There are likely to be regional differences and not all kids paid attention to what Mom played or had fond memories of it.