Some time ago, I drilled and filled holes through my skegs for toggle bolts so that I didn't need a strap to go all the way around the boat. I was very happy with the situation.
Until I noticed that there were some cracks in the skegs that weren't there before.
<I have pictures, I'll modify this post with pictures when I can.>
Today I did some investigation, sanding and patching. I now believe that it was not the stress from the bouncing on the trailer. I think it was because I din't get the holes sealed as well as I thought. I used red oak for the skegs and I think some water got in and seeped throught the wood pores and caused it to stretch a bit.
I sanded everything down and recoated with epoxy and graphite powder.
I also found another area where the skeg had rubbed against the trailer and scraped it down to the wood. That must have been recent, as I had found that before on the other skeg and patched it already.
Too bad it's such a pain to work on the skegs under the trailer.
I will continue to experiment with this and let everyone know.