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A marine surveyor has confirmed there is damage on the boat which sank in Auckland's Waitemata Harbour on Anzac Day drowning two young children.
However, police said today they were not sure if the damage happened before the sinking and had caused the 7.3 metre launch to sink, or if it happened as it sank.
The marine surveyor inspected the boat and held water trials this week.
Police divers recovered the boat and found one of the bungs missing but police spokeswoman Noreen Hegarty said they were not sure if the bung was missing when the boat was launched, about 15 hours before it sank.
"We don't know when the bung went missing or if it was in the place it should have been," she said.
One theory was that when the motor was started to head to shore after water was noticed in the boat, an abandoned anchor rope may have wound around the propeller and dragged the stern under.
However, Ms Hegarty said no rope was found on the propeller of the boat's outboard motor when it was salvaged.
Erina Rowles, eight, and her brother Travis, five, were trapped in the cabin when the boat took on water and sank stern first at Tarahiki (Shag) Island east of Waiheke about 2am on April 25.
Four adults, including the children's parents Lindsay and Tania Rowles, escaped and sat on rocks for nearly five hours before they were rescued. The bodies of the children were recovered soon after the adults were rescued.
The group launched the boat about 11am on April 24 for a fishing trip.
- NZPA
