What I've noticed when I've listened has been frequent, but short, breaks. It seems to run two or three songs followed by two or three commercials. I've never bothered to calculate how much airtime that is total over the course of an hour, but my understanding is that commercial breaks are limited to 90 seconds or less outside of prime listening hours.
It wouldn't make my list of Yacht Rock tunes, but that's ultimately a brand more than a real format. As RadioFan mentions, what makes the playlist ultimately depends on what the target audience says it likes. Few, if any, listeners are going to turn off a song they like simply because it doesn't fit their definition of Yacht Rock. The average listener to the station had probably never even heard of Yacht Rock until hearing it mentioned on The Wave. The concept those people have of it, if they even pay attention to that, is what they're hearing when they listen.