November is a good time for diving in SA, Sodwana, Tofu and Protea Banks / Aliwal which are very close together from both perspectives, good weather and generally good surface and underwater conditions and it is also a bit quieter before the Christmas season rush.
Diving along the SA coast is an all year round affair, I know some folk have a favourite time of year and thats fine, but as far as I am concerned there is good diving year round, there are of course certain seasonal experiences like the sardine run which brings a lot of big pelagics in its wake but you stand just as good a chance of seeing one on any dive at any time.
Its obviously summer now so the weather is good and sun and hot weather always makes diving more enjoyable, but even winter conditions are mild and in water temperatures in those areas you are looking at seldom goes below 18 degrees centigrade.