Exposed lead on keel

Paint it

New bottom paint? This really isn’t a big deal. If your other bottom paint looks good then just do a little sanding (with a respirator, obviously) and paint that section. If your whole bottom needs painting then sand the whole bottom with 80 grit (spending a little more time on the chipped sections) and then repaint. The 80 grit leaves scratches (keys) for the new paint to lock onto.

If you know what kind of bottom paint is on it then find a compatible bottom paint (they’re not universally compatible). If you don’t know then find one with the most compatibility across paints. What you don’t want to do unless unavoidable is to need to sand down to gel coat because that’s a lot of work.

It's only an issue if it's like that because it's been grounded against some rocks. If you are worried check the keel bolts and if you aren't comfortable doing that pay for a surveyor to do it for you, would take them like less than 10 minutes.