Specialities are 1-2 day courses focusing on a special kind of diving.
Wreck Diver:
Do your Adventure dives on Thistlegorm. For the full Wreck Speciality, we arrange for you to split your dive holiday between Dahab & Sharm
If you've done your Advanced course, you will have already done some dives that credit towards a PADI Speciality - Deep, Navigation, etc.