Sharjah behind al tawun opposite to aquarium is a good place... but now a days no bites.. you can try business bay bridge, umm al qwain near palma beach and behind police head quarters. Ajman beach is also good... i am still searching for better place..will let you know when i find one...
I can recommend fishing in Ajman on the rocks opposite Kempenski hotel from Hamria free zone side apart of Catfish and Stingrays I get lots of barracuda's, shaeri's and Safi (Arabic names) A friend got some Cobias last weekend