The heavy seas and strong winds that have battered the broken vessel Rena this week are set to ease over the Easter break, but not before large amounts of debris washed up on east coast beaches.

Days of rough weather in the Bay of Plenty pounded the container ship grounded on the Astrolabe Reef off Tauranga, sending the stern below the surface, almost six months after it grounded on October 5.

Waves of up to 12m and winds of 50km/h were recorded at the wreck earlier this week.

Sixteen containers were lost during the storm and oil continued to trickle from the wreck.


Cuts of meat were among items from the ship that washed up on Coromandel beaches yesterday.

Debris, including plastic beads, timber and wheelbarrow parts, spread over a wide area including Matakana Island, Waihi Beach, Pauanui and Tairua, said a spokesman for environmental recovery specialists Braemar Howells.

However, the weather has started to calm in the region and would continue to so during the Easter break and into next weekend, said head analyst Philip Duncan.

"The swells are still quite big but they're nowhere near what they were - they're down to about 1-2 metres.

"They're not major seas, it's just going to be a little rough for the rest of the weekend."

Southerly winds coming through the area would help to flatten the seas, said Mr Duncan.

"The weather will be gradually improving and winds dying."

A south-westerly change was expected early next week, with improved weather conditions likely to continue into next weekend, he said.

Anyone who sees debris is asked to report it by phoning 0800 333 771.

- APNZ and New Zealand Herald