Damaged as in dinged/chipped, or damaged as in snapped off?
I nailed a rock at about 20 MPH while heading out ab diving; took a 3" long crescent about 3/4" deep out of the front of the skeg. A couple of minutes with an angle grinder, a couple of layers of colored eopxy, reshape with the grinder, and it's been working fine for about 6 months.
Skeg doesn't do a whole lot anyway. Some (poor) prop protection, and a bit of rudder surface for power-off steering; that's about it as far as I know.