They stay in place. Do not drill all the way through the oar tower. I stopped about 1/8" from going through, this keeps it from falling out the bottom. Springs will hold them in. I left about 1/8 sticking up to keep oarlock from rubbing top of tower. I only have one trip on them through New River Gorge but they seem to be great.
I am an American Whitewater member. One of 6300. There are an estimated 100000 paddlers in the U S. If you are not a member you should join. AW is fighting for our rivers everyday and could use some help.