The north of Egypt is different area and there is no recreational diving going on up north because the visibility is poor and there isn't much to see as far as reef and corals go. There are a few old relics beneath the Mediterranean but they are not as popular as Red Sea diving.
Hurghada and Sharm el Sheikh are on opposite sides of the gulf which one might consider the north of the Red Sea but as far as Egypt's boundaries extend I would place then in the middle third because other cities such as Ain el Sokhna, Zaafarana, Abu Zenema, Abu Redeis, Ras Sudr are further north.
Hurghada has indeed been damaged from the vast number of tourists that visit Egypt every year. Divers and snorkelers along with the boats that carry them out to sea have damaged the beautiful marine life that once flourished beneath. Hurghada is a cheaper getaway therefore has more tourists than Sharm el Sheikh and that explains the difference in quality between the two cities. Compared to what Sharm el Sheikh once was the quality of corals that inhabit its' waters has declined but I still spot a few manta rays and green sea turtles most of the time I visit.
Unfortunately I do not dive in Hurghada often anymore however during my last trip a few months ago we were lucky to be joined by a large group of dolphins; magnificent creatures. I would still advise beginners to start their diving course there because they can cause less damage and for a beginner, diving is an overwhelming experience.
There are virgin marine national parks that have developed stricter rules and regulations to prevent damage to the corals and marine life. Ras Mohammed is one of the best area to dive in Egypt, it is a national park with both marine and wild life preservation. Further south is Marsa Alam famous for it's schooling Hammerheads and even further are the Brother Islands and Berenice right before you hit the Sudanese border.
