Dubai - Scuba Shade; Al Habtoor Grand - Dubai Marina area.
Dubai (West Coast ) Diving is limited to wrecks, the seas can be lumpy because of the wind coming down the gulf. The best wrecks are Miriam Express and Zainab, both 30m wrecks and both around a 45 min boat ride.
Vis can be poor especially in the near shore sites, it can be good further out, or equally as poor - especially in the late autumn through late spring when the water cools enough for Plankton blooms. In the Summer because the gulf is shallow, the sea temps can reach 36- 38C
East coast diving is reefs (with a few sunken barges)
You need to drive to Korfakan (Dibba) which is a 2 hour run from Dubai
Choice of centers are:
Al Boom
Divers Down
Free Style Divers
Sandy Beach Dive Centre
All are good operators, Al Boom tends to have the less experienced divers, they also IIRC have s bus shuttel service from Dubai
Vis can be great or pants
For Equipment Sales
Al Boom - Al Wasl Road, Jumeriah 1 Who are Apex/Aqua Lung
Dive Garage; Currently in Dubai Investment Park 2 - Dive Rite, Shearwater, Suunto agent and repair centre
BOTH Dive Garage and Al Boom have very good Service centres. My regs go to Al Boom because the Tech manager is a Scot Expat, knows his stuff and has pretty much written the book and worn the tee shirts out
Hope that helps