You are spot on Rudy. Seabreezes work when the cool sea air rushes in to replace the hot air that has heated up on the land and risen. The further north you go, the further the hills get away from the coast so hence lots of flat hot land.
Even if you get wind at Seacliff, you will usually find its much windier at Semaphore on a seabreeze.
Just track what the wind is doing on the live graphs on here at Outer Harbor and that will give you a fair indication of what is happening at Semaphore.
Good luck