Another witness, who was driving across a nearby bridge during the attack, told local media: "I saw someone swimming, but I couldn't see their body, only their legs."
While many of her childhood friends had settled into professional careers and family life, she was into regular partying and indulging in excessive behavior on weekends.
Still missing are Morgan Stanley chairman Jonathan Bloomer, his wife Judy, and U.S. citizens Chris Morvillo and his jewelry designer wife, Neda Morvillo. All are now feared dead.
According to the New Zealand Herald, Ayla's phone was the only one with a charged battery, and she was helping with communication with the first responders.
The investigation will examine whether the crew took the necessary precautions given the weather forecasts and if any crew members might face criminal charges.