Lock your car doors, and keep the windows closed. Keep the personal items and luggage in the trunk, rather than on the seat of the car. Plan your route in advance, and use maps. Park in well-lit areas, and do not pick up strangers. However all medical treatment must be paid for, so you should purchase travel insurance for your stay.
Tap water is safe to drink throughout South Africa.
You can swim safely at beaches along the entire coastline. You shouldn't swim in rivers and lakes in the eastern and northern regions, as the bilharzia parasite may be in the water. Warning signs are usually posted. The Eastern Cape is bilharzia-free. No vaccinations are required of visitors coming from the United States or Canada.