Here are examples of some specialty courses:

Enriched Air Diver
Deep Diver
Multilevel Diver
Underwater Photographer
Underwater Navigator
Wreck Diver
Night Diver
Underwater Naturalist
Drift Diver
Boat Diver
Dry Suit Diver
Ice Diver
Search and Recovery Diver

For more information see the "Specialty" category under the "Training" section. If you have further questions don't hesitate to get in touch.