The first step in the right direction to protect coral reefs, is to not cause any more stress to the corals. Divers with reckless diving behavior will definitely destroy every opportunity the corals have of surviving the extreme environmental challenges they are facing.
One of the most important rules that you have to follow as a diver is not to touch anything and watch your steps/kicks. Preferably if you can also choose an operator with sustainable practices.
If you feel like doing more and getting involved in the issue, there are plenty of opportunities for you. If you want to be a part time scientist you can join the global data collection team and report what you see on your dives.
These are just waiting for people like you to join the research team:
- NOAA has a clear and comprehensive survey for you to fill out, wherever you are in the world.
- Reef Check Malaysia is collecting bleaching data to help it mobilize teams to badly affected areas, but is interested in data from other regions as well.
- Green Fins Thailand, in conjunction with the Phuket Marine Biological Center, is calling for reports.
Everywhere you go and every step you take, you have an impact on the world, 
both above and underwater. Meaning that the choices you make both as a diver and citizen or tourist will affect the problems that the corals are facing. Day to day choices matters, take the bike instead of the car a day or two, and say no to the plastics you don’t need. And last but not least, make sure your diving behavior is responsible to the reefs and every other animal in your surroundings
These may seem like small actions to deal with enormous threats, but your choices are no small thing. Tourism is one of the fastest growing industries globally, and each time someone makes choices to lessen his or her personal impact, either at home or away, it will protect coral reefs.
