At 0954hr a 11m launch with 4 POB notified Coastguard that it was at White Island and had engine problems. The engine management system for one engine was not working and the engine was dead. The boat planned to proceed to Whakatane slowly on the one good engine but would need assistane to cross the bar. Weather conditions were reasonable with clear visibility and 12-14kt wind from NW and 1m swell.  At 1540hr the launch reported that it was waiting 0.5nm off the bar.  At 1545hr Whakatane Rescue was tasked to assist the launch and towed it through the bar. Both boats were safely back in port at 1630hr.