Tim, yes airboat prop blades cop a hammering, the small chunks and chips in airboat (or aircraft) leading edges are pretty common and don't need attention.... but some that are bigger or deeper chips, especially closer to the hub.... do need attention ASAP.... A deep chunk out of the leading edge close to the center can throw a blade.... one coming off can literally rip the motor out of the boat....
The small rough normal look of a prop can often be repaired with a file or sand paper, but deeper chunks and chips need a proper repair. On Ivo and Warp, I have always used araldite or superglue where you mix the resin and catalyst..... first picking any debris out of the chip and looking for cracks, then filing/sanding the damaged area, making sure to leave it rough, but clean. If there is any cavity, I have used some fiberglass matt to push into the hole.... I have seen others push poly styrene beads in holes so the glue doesn't end up disappearing into the hole.... then apply the glue, working it into every groove and scratch of the rough surface you left on purpose, to give the glue plenty to hold onto. When the glue is on you can get some clear packing tape and cover the new patch which helps keep its shape and dirt out while it cures. After curing, peel off the tape and sand smooth.
There is new glue now, where you simply clean the 'wound' put the clear part A on, then sprinkle the catalyst on the glue, cover with tape and sand once cured.
I am a big fan of 'helicopter leading edge tape' which is a clear tape about 2" wide (you can get 3" and 4") which is put on the leading edge from about 1/3rd out to the tip of the prop.... it will stop the sand blasting of small particles, and will reduce but not prevent damage from rocks/birds etc...
I use the same repair method on wood props, but rather than file out the 'valley' of a chip. I pick any loose wood or debris out with a scriber and feel for large cracks or splits, and sometimes will drill small holes into the damaged piece, to give the glue somewhere to go into for better grip.... then I use the same araldite/superglue and spread in the same way.... followed by tape.... then sanding once cured.
If you have used a lot of glue on one blade repair, you must balance the prop, or risk running it out of balance and stuffing the gearbox.....