The ATSB has found that the speed boat Norma Jean was travelling too fast in the darkness to avoid a collision that claimed four lives.
The Australian Transport Safety Bureau's final investigation report states that the Norma Jean's probable high speed was inappropriate in the dark conditions and the use of the boat's internal lighting may have restricted the ability of the boat's skipper to see the barge until immediately before the collision.
At about 1500 on 12 March 2007, the unmanned barge Seatow 61 was anchored about three miles off Carnarvon, Western Australia, and the barge's anchor lights were set to operate automatically. The barge had been anchored in this position following advice from the harbour master.
At about 0610 on March 18, Norma Jean left the Carnarvon boat harbour and, at about 0625, it collided with Seatow 61 and sank quickly with the loss of all four of its occupants.
The ATSB investigation also found that, in 2002, another Sea-Tow barge had been involved in a similar accident in New Zealand and that Sea-Tow did not take proactive measures to prevent a recurrence. Further, the harbour master for the port, who was based in Perth, was not sufficiently aware of recreational vessel activities in Carnarvon to be able to adequately assess the risks posed to recreational vessel skippers by the presence of the anchored barge.
The ATSB reports safety action already taken and has issued four recommendations and four safety advisory notices with the aim of preventing further incidents of this type.