Used to have a 26 1/2 foot cabin cruiser. We used to go out on it quite a bit. We don't have it anymore now that we live on the smaller lake. Boats are a blast and the next best thing to living on the water, is living on the lake
I am sure your dad will enjoy it, just make sure he knows how to navigate open waters and to watch the weather
We have been stuck in huge storms that scared the shit out of us.