Sidewall hatch cutout

I need some help. I am using the Kuffle Creek 10' Comet plans and Steve Frederick's plans to build my trailer. Problem that I am having is neither set of plans gives details for the depth of cut (for either set of plans) or the radius of the cut (Steves plans) for the hatch offset into the side walls. Ultimately I will be using Steves radius cut since I like the way it flows with the overall Comet shape.
Can someone give me some insight as to how this cut should be made? Does the cut extend all the way to the tear tail end or does it taper?
Thanks in advance,
Greg
Can someone give me some insight as to how this cut should be made? Does the cut extend all the way to the tear tail end or does it taper?
Thanks in advance,
Greg