Question: what qualifications do you need to be an underwater photographer?
Answer: Take an interest in marine life. Ideally you will have (or be in the process of getting) a marine biology degree. ... 
Watch documentaries. ... 
Be prepared to work for free or very little money while you gain experience. ... 
Learn to edit. ... 
Get production experience. ... 
Sell yourself. ... 
Persevere and be Patient.