Speciality Courses are a fantastic way to develop and improve your diving skills.
Unlike some of the more general courses where there is lots to cover in a short time, with a speciality course you and your instructor can concentrate on a single subject / skill often in a small group.
 
PADI Speciality Courses involve online E-Learning course and between 2 and 4 dives (specialities requiring 4 dives are held over two days).
 
Speciality Courses can be credited to or from the PADI Advanced Open Water course, for instance the Deep Speciality course is a 4 dive speciality if you already have your Advanced Open Water qualification you will have already completed dive 1 of the Deep speciality course and you will only need to do 3 dives.
 
You may even want to become a PADI Master Scuba Diver by undertaking 5 specialities, Advanced Open Water and your Rescue Diver Course.