Very familiar with "here today, gone tomorrow" cover, as many of our lakes are prone to flooding & heavy drawdown currents when the lakes are drawn back down to Pool. Seems like, also, that our KDFWR knows that the thermocline normally sets up around the 15ft depths and place their artificial and natural cover items no deeper than 15fow.
I have the GPS coords to hundreds of those KDFWR cover items and even some for a lake in Tenn. .... and I've already experienced some of them no longer existing or anywhere near the coords assigned to them. I've also experienced many laydowns & timber piles having disappeared after serious flooding. These are (in KY) mostly flood control lakes & not power generation lakes.
So yeah .... you've got to keep up with the changes or your "honey hole waypoints" are gonna be wasted info & a waste of time.