And what about:

– What was your best dive ever?
– What is your favorite dive destination?
– What was your worst dive gear purchase?
– What dive computer would you recommend?
– Did you ever dive in cold water?
– What was the first dive purchase you did?
– Where did you get certified?
– Why do you like diving?
– How often do you dive?
– Do you like muck diving?

Maybe not 20, but with the previous answer combined you probably have enough 😉