I give it a bad rap there, but really it is one of my favourite spots. Probably mainly because it feels safe.
Vetch's is the beach in between the North harbour breakwater and Vetch's reef which I understand is the remnants of some man made thing. Not sure exactly the history. The breakwater runs directly perpendicular to the beach and forms the Southern barrier of the sailing area. It is BIG boulders and while you may be able to haul your little body delicately up those boulders to safety you can be darned sure that your expensive kit should stay off them!
Vetch's is bounded to the North by the reef. The reef runs diagonally out toward the breakwater. This is a nasty fact which means that as you get further out to sea, your reaches must get shorter if you wish to stay within these barriers. Not ridiculously short, mind, but you will get some gybing practice!
Check out the following link of Durban Bay for a location of Vetch's: