To hire one of the available jet skis, the only criteria is that the operator is over 16 years of age (no boat license required). There is no age limit for passengers. Life jackets are supplied and there are 800cc or 1100cc jet skis to choose from.
If you're familiar with Goolwa, travel along Barrage Road - Goolwa Jet Ski Hire is just before the mighty Goolwa Barrage (a huge structure separating the fresh water of the River Murray/Lake Alexandrina/Lake Albert from the salt water of the Coorong).
From Adelaide, it will take around 90 minutes by car.