Ok, I'm trying to picture this. Why do I tie a bowline at after the small hole? I understand tying one end to the loop at the top of the S hook, and the ring and thimble at the top of the forestay. But still not able to figure out how to use the drilled hole and bowline.

My halyard goes: Loop on S hook, locking ring, thimble, down.

Does the other end go through the triangle and back to the drilled hole on the S hook?