Four passengers were injured and 47 vehicles were damaged on a hair-raising Interislander crossing last year, but an investigation has found the decision to sail was appropriate.
The Transport Accident Investigation Commission has released its report into the Aratere's trip from Wellington to Picton in high seas in March 2006.
Thirty two private vehicles, nine camper-vans and six commercial vehicles were damaged when cargo lashings failed, while four passengers and a crew member received minor injuries.
Investigator Captain Iain Hill says the decision to sail was appropriate, but the conditions deteriorated much more quickly than expected.
He says while it was a frightening experience for passengers, the ship was never in any danger of capsizing. Captain Hill is confident The Interislander has already put all the right safety precautions in place to ensure a similar incident will not happen again.
The Interislander line says it has carried out a full review of all its operations following the incident.
General Manager Seamus O'Sullivan says additional lashings are now attached to heavy rail and road cargo once swells on the Cook Strait reach four metres or more.
He says sailings will be suspended if it looks like waves will reach six metres.
- NEWSTALK ZB