The tourist boat that ran aground near Akaroa Heads - will be submerged before it's recovered

The Black Cat Cruise vessel was carrying 38 passengers and three crew when it ran into trouble on Saturday - all were safely rescued.

Environment Canterbury says the boat will be sunk deeper to prevent further structural damage from wind and sea conditions before it's lifted out.

Transport Accident Investigation Commission Chief Investigator of Accidents Louise Cook the inquiry is non-blame - and will address systemic issues to ensure this doesn't happen again.