Get on the water and ride. Jet skiing in Zanzibar takes place along the coast, mainly around Kiwengwa and other beach areas on the east and north side of the island. The water is warm, clear, and calm enough to enjoy the speed without rough conditions getting in the way.
No experience needed, you get a briefing before you go out, covering how to handle the jet ski, where you can ride, and basic safety. Sessions are short and straightforward. You head out, ride along the coastline, and come back. Simple as that.