The Red Sea not only has spectacular diving, it also has spectacular regulation of diving.

Dive tours in Egypt are very affordable.  Your package generally includes airfare, four star hotel, meals, and one dive each day.  The Egyptian government goes to great lengths to protect their reefs from damage by tourists.  Hence, you see signs like these at dive shops at the resorts.

If you are more adventurous, and if you want to see even more pristine reefs, then dive on the reefs of the southwestern Red Sea.  The reefs off Eritrea and Sudan are untouched, and if you have your own yacht,  compressor, and gear, you can dive to your hearts content.

If you are even more hardcore about spectacular diving, then get a job in Saudi Arabia and become a diver in the eastern half of the Red Sea.   When we worked in Arabia, many of our friends did undersea photography off the Saudi coast.