At 1005hrs a jet ski reported an engine problem 1km off the Pump Shed E of Tarawera River requesting a tow; 1 POB.  “All Stations”resulted in a vessel responding.  Sea conditions good, low swell, and 3-4kts wind from SSW.  Successful tow back to Thornton at 1300hrs.  Thank you to the Good Samaritan.