"Those are great, but keep in mind that the alternator on a typical boat engine is really small and will probably take 8 or more hours of cruising RPM to bring a dead battery back to a fully charged state, maybe longer if the boat has a big electrical load and/or more than one battery. "
I was having that problem on my house battery after spending all day on the sand bars. It would never get time to charge in the ride back to the marina.
I fixed it when I supplemented my charging system with a decent solar panel mounted on my stern. When my boat is at the dock or stored it is always trickling my house battery (my engine battery does not get used at sandbars and gets engine changed).
I've been using the older 5w model of this one for 3+ years with good results.
https://smile.amazon.com/dp/B07QNM26Q7
If your lighting is all LED, it may even counter a light being on when docked.