I could write a dozen disclaimers before I start on this. Just to cut to the chase, when over the air DTV works, it works. Except for a narrow fringe area, you either have clear pictures and great sound or a blank screen.
For the price of six months worth of cable, we bought a 19" Toshiba DTV with built in DVD player. We use the legacy analog Shakespeare pizza antenna that came with the boat. We have a line of sight view to the Sutro Tower about 14 miles from Penny Lane. We now get the broadcast networks (ABC, CBS, Fox & NBC) and the San Francisco area independents. Most of these channels have subchannels for lifestyle programming. The all weather channel is the most useful. We use Netflix to watch last year's HBO/Showtime/USA stuff plus movies for about $15/month.
If your cable bill at your slip is getting too high for your usage or interest, you may be in a DTV coverage area that provides basic TV for free.