the big picture
Cape Town is a meca for kitesurfing. An abundance of spots cater for every conceivable taste and wind direction. The biggest concentration of spots are in the bloubergstrand and big bay area, on the eastern side of Table Bay. They are perfectly located for the consistent south easterly wind, affectionately known as the Cape Doctor. The spots are dotted along the coast, from south to north (see the map below).
when should i go
From November - March the south easter delivers the goods, with December - Feb the peak months. The Red Bull King of the Air is a spectacle not to be missed, and the window is typically set around the end of Jan / beginning of Feb
Conditions and Weather forecasting
The wind will regularly hit 30+ kts (55+ km/h). On days where the south-easter is forecasted you can be guaranteed wind will blow - you just have to wait for it. When there is west in the forecast it's a lot less reliable. The wind also progresses from the south to the north. Spots at the south end like Sunset/Dolphin beach will get strong first, and the wind will push further north as the day goes on.
Everyone has their own favorite forecasting sites and tools. In Cape Town windguru seems to be pretty good. You can use WindGuru - Kite Beach for the forecast (if you are there a while the pro membership is worth it), and on the day keep an eye on Best Kiteboarding wind station to see if the wrath has arrived. Also a couple of webcams come in handy: Big Bay and Kite Beach.
LogisticsYou will likely need a car to get around, unless you are staying in big bay or blouberg near the beach. There is ample free parking all along the coast. Generally there is plenty of room to rig and land on the beach, with the exception of Big Bay at high tide (see our map below for more detail). Don't leave valuables visible in your car while you are in the water, and be careful using a key lock on the car - you are better of getting a waterproof pouch to carry your key on you.
Bloubergstrand and Big Bay Area Map
The map shows the main spots, rigging areas (unless explicitly marked with green/orange, rigging is anywhere on the beach), parking & amenities. Zoom out to view the larger area