I've been there a few weeks a go, in Faro you can kiteboard on the lagoon or at sea. Mostly the wind is offshore there so the local guys there are all on the lagoon. It's verry small and crowded.
But if you drive 20 km past Faro direction Albufera, you can go to the beach at Villamoura richt side of the harbour, nice beach and nice waves. The wind is sideshore at that spot. No crowds there.