I used bead and cove strips and I thought I was doing a good job laying them down, although this is my first boat.

I would like to know what I did wrong

Marc-
You probably didn't do anything wrong. B&C strips work pretty well on canoes with gentle curves, but IMO not so well on kayaks. I've used B&C on both types of boats, but don't use them on the kayaks I build nowadays.

If you make up a couple of large cardboard shapes showing the cross-section of B&C strips and see how the strips behave as you 'rotate' to form sharper curves, you will see that there isn't 100% tight contact between the strips. With firm pressure and soft wood like cedar you can press the strips closer together; with harder wood and tougher curves and twists gaps develop more easily. (Staples help to hold them together, but let's not start that discussion...)

Most other folks probably won't even notice; try not to focus on those small errors....though I know it can be difficult. I'd recommend an epoxy seal coat if there are gaps. After glassing, the 'flaws' will probably be less apparent.