George,
Bill and Ross address the hatches both with great points. I just thought to add a small point that has helped me on several builds. Before I bond the two halves together I go over the joint with a long sanding board. What I do is use a board that is longer than the kayak is wide and let it run from one side to the other like bridging the sides and sand it well. This puts the exact angle on the edge of the strip so it will mate with the other half. you can see as you sand when the fresh edge meets the outer edge of glass it is at the right bevel. By sanding back and forth the length direction, not the width direction, You get a super tight join between deck and hull. This will help greatly with a tight seam and will look like the other tight strip seams.
I hope you don't stress over this part, It's one of my favorite parts. After the joining of the deck and hull you have a kayak instead of just parts.
Good luck and have fun building.
Clayton