For safety reasons, speed limits are imposed on waters of South Australia where high-speed boats would present a hazard to other aquatic users ie

• various harbours
• metropolitan beaches
• some sections of the River Murray.

If you intend boating, waterskiing or using PWCs (Personal Water Craft) in unfamiliar areas, make sure you find out if there are any speed restrictions. Details are available from Recreational Marine enquiries or local Marine Safety Officer.

Outside speed limit areas, the following speed restrictions apply to all boats under the following conditions

4 knots applies

• within 50 metres of
  • a person in the water
  • a vessel or buoy on which is displayed a flag indicating that there is a diver below (International Code Flag A)
  • a person in or on a canoe, kayak, surf ski, surf board, sailboard or similar small unpowered recreational vessel.
• many waters within marinas and restricted areas
• to all Personal Water Craft (jet skis, wave runners etc) within 200 metres of the metropolitan shoreline (between Outer Harbour southern breakwater and southern end of Sellicks Beach) and the backwaters of the River Murray unless zoned otherwise
• within 30 metres of any other vessel (whether stationary or underway) that may be adversely affected by your wash
• within 100 metres of a ferry crossing on the River Murray
• within a mooring area or boat haven
• within 30 metres of a jetty, wharf or other place at which a boat is being launched or retrieved.

10 knots applies

• while a boat (not a PWC) is being operated by an unlicensed person (minimum age 12 years with a licensed person in charge.)

Speed restrictions apply to many local areas. These restrictions are often on signs located near boat ramps.