An assessment of a sunken 50-foot vessel over the weekend has found its diesel tanks are empty, says Waikato Regional Council.

The vessel struck rocks near Motukorure Island – also known as Centre Island – sometime before 3.45pm last Wednesday and sank with 1300 litres of diesel on board.

The skipper and passenger were uninjured.

Divers visited the site over the weekend and established there is no diesel left in the vessel’s fuel tanks, says Regional On Scene Commander Cliff Gibson.

“Based on this information, it’s believed there was a slow leak from the tanks in the hours immediately following the sinking.

“The absence of any diesel or oil on the surface of the water over successive days leads us to believe the diesel was taken away from the island and shoreline on the outgoing tide, with minimal impact on the nearby coastal and marine environment.”

The council is continuing to liaise closely with the salvors.

“A timeframe for the vessel’s recovery is yet to be confirmed and is dependent on favourable conditions. However, the salvage team has indicated they will try to raise the vessel to shallower water on Wednesday so it can be further assessed and the next steps in the recovery decided.”

Salvors have indicated they would use a crane on a barge to lift the vessel from where it currently sits 20 metres below the surface of the water. 

“It’s important this process is not rushed and that every precaution is taken. We plan to have our maritime officers at the scene during the vessel’s recovery to ensure the risks to the environment are managed throughout the operation.”