A tractor of that size can handle a flail mower, and there are many models that can mow off to the side of the tractor rather than behind it. I'm going to look at one this afternoon to mow my pond bank edges and I'll probably be coming home with it. If you search for Cosmo FRF 165 online you'll get an idea of what it is. With something like that, he can stay 5' from shore with the tractor and still reach everything with the mower. Because they don't use sharp blades, he doesn't have to worry about how many fingers he'll have when he's done.
