They are correct......... a seabreeze is created on a hot day when the land heats up ( obviously above the sea temp ) late in the afternoon as the sun gets lower4 in the sky and the general air temperature begins to drop the land is still hot...... this causes the hot air to rise as it rises it has to be replaced with something usually it is cooler air over the water that is drawn in creating the inshore seabreezes........ I say inshore because seabreezes are only created near land.
Unfortunately if the prevailing winds are already blowing offshore eg: an easterly in Melb they can compete against the seabreeze therefore lowering or negating its effects.
In my experience, on really hot days you don't get a strong enough seabreeze. Really hot days are usually caused by northerly winds in melbourne, so seabreeze and the northerly tend to cancel each other out. In my opinion the best conditions are light SW air flow (or at least no wind from the north), sunny day, 25-30 degrees. the arvo breaze will add to the SW air flow and you get a decent 20 knots by 4pm.
And yes, the seabreeze is usually S-SW, and stronger closer to the city. St Kilda sometimes has 5knots more than Hampton.
