Mounting trolling motor on round gunnel

Setting up my new boat and need to find a way to mount my trolling motor to the bow. This is your classic transom mount trolling motor with reversed head. My boat is a Lowe L1440M and has a round gunnel. Anyone have a good solution for mounting to the round gunnel?

I was going to order a mount from AK McCallum but they are out of stock (see attached pics) from this link:
https://www.akmccallumco.com/store-misc.htm

I could make one out of 2x4s but not sure how to bore the half circle. Any woodworkers know how to bore a half circle as shown?

Dor you have a deck or any sort of platform in the bow of the boat

Use a router, should work just fine on the 2x4's. If you do not have one, clamp them together tight enough and drill a hole the size of your gunnel.

Bore through board with a paddle bit from each end, then rip it lengthwise. Easy way to do it.

Thanks for the suggestions. I do not have a deck on the bow at this time, probably won't add one for a while cuz I don't want my kids falling in the water when I take them fishing