Working very close to Vetch's, I have snorkelled and speared on the reef many times. It is a brilliant place to start out a spearfishing career.
On the reef I generally go for the BIG mullet that come and cruise over the shallow areas. This is for target practice (try shooting a 3kilo mullet) and they make good bait for the bigger Nunus off the beach.
On the outside edge of the reef I have seen big shad, stumpies, pickhandle barracuda and all sorts of shootable fish. Personally I just enjoy being in the water and Vetch's can be amazing in the right conditions. Besides the spering, I have seen spotted eagle rays, honeycombs, brown skates, cuttlefish, squid, crayfish, a K1 canoe, dolphins...
AND... You have Limestone (not actually made of limestone) reef just off Vetch's. Here you can shoot almost anything, even couta and snoek...
So get out there and enjoy the sea, even if you don't get fish, the more you dive the better you get and the more confidence you gain.