If a class is fully booked you can join the waitlist and receive an email once you’re placed in class, which will happen if someone early cancels from the session (early cancellation is possible until 9 hours before class commences).  The booking system will move you from the waitlist up until four hours before class if possible, so it’s important to keep an eye on your inbox until that time.

If a class is fully booked AND the waitlist is also full, the SIGN UP button will not be available on the timetable and it is highly unlikely that you would be able to get a spot in that class.