Don`t worry about the sharks too much, the reports of all the recent attacks and sightings are mostly in False Bay, Cape Town, in the colder water found there, Great Whites aren`t too fond of warmer water, Port Elizabeth has a much warmer current along it`s shoreline. I`ve sailed a LOT in PE and only ever seen Raggies (Ragged-tooth sharks), they are a bit like the bulldog of the shark world, all teeth but actually quite docile - divers even go looking for breeding grounds so they can swim with them !
In PE you are likely to see a lot of dolphins, expect schools of over 40 to surface and swim around the boats at the start line while you are waiting to start a race - we had that at the Dart Worlds in 99.

Cheers
Steve