To become scuba certified, you have to do something like 10 hours of book learning, and then 7 different dives/levels where you prove your underwater skills. I got stuck at numbers 3 and 4. One of the skills on this dive is that you have to take off your mask underwater and replace it. After that, you have to take off the mask underwater, swim for one minute, and then replace it. I could barely let water in my mask before freaking out on the first two days. After 3 instructors.. and 3 dives.. I did it!! Or in the words of my scuba instructor, "You owned that skill!" I guess the third time really is the charm!