dont know much about it. what kind of diving/work does comm…

It covers a wide variety of roles from underwater construction, welding, cutting, salvage, inspections and repairs on ships and underwater infrastructure, diving into nuclear reactors, fish farms, laying underwater cables, offshore drilling, etc.
Certain roles require DMTs (Diver Medical Technicians) and my paramedic experience gives me a leg up in filling those roles so I will try to get into offshore rotations doing that but I will need to slug it out doing inshore roles before I can find that sort of work.