A vessel near Emu Point witnessed the explosion shortly before 2pm, Senior Constable Nick Hall of the Marine Rescue Centre confirmed.
Two people injured in the blast were pulled from the water and transported to hospital by ambulance services, and have since returned home to recover. Police have opened an investigation into the incident, with early indications pointing to a fuel vapour line catching fire, which reportedly caused the jet ski to split apart and sink.
Senior Constable Hall noted that the jet ski involved was 20 years old and had received annual servicing, yet the incident occurred regardless.
"The Police Maritime Unit are concerned that this isolated incident may indicate a 'hidden' situation for owners of older jet skis," Senior Constable Hall said.
Officers involved in the water rescue are urging jet ski owners to check their craft for hidden issues. Fuel lines and fittings deteriorate with age, and that degradation may not be apparent during routine checks.
"Please check all fuel lines and fuel fittings as these items perish with age, and we encourage owners to replace such items periodically," Senior Constable Hall said.
