I just took my class last month. I was nervous about "passing" too, but it was easy. Basically, you should be familiar with the important points in the reading material. If you have been able to pass the quizzes (knowledge reviews) you should have no problem withthe written test. As far as the checkout dives go, if you are having difficulty with anything, your dive instructor will be able to go over it with you until you get the hang of it. You don't need to be perfect at everything to pass. You DO need to show you can perform the basic skills and feel comfortable enough doing them. I kind of see the OW cert as similar to an auto learner's permit. I still have a hell of a lot of practice to get good atthis, but I proved I am capable of doing what i need to do to practice safely.