Kelvin, sorry to say I beat you to the "hot spot" in Victoria Gardens! I would have thought that around the marina in Briton Ferry you should find some, anywhere where there is weed & stones.
Otherwise you will have to make your way along the foreshore from the Jersey Marine roundabout back towards the Queens Dock ( be careful of the poofters), there was always good crab pickings off the Queens Dock Breakwater, but now its fenced off you have to walk from the Ford Factory to get to it!
blueskip