A group of five Greenpeace activists who chained themselves to the decks of a climate research ship have been convicted and discharged.

The protesters stormed the Niwa climate and ocean research boat Tangaroa while it was berthed in Wellington in November last year.

They claimed the ship had been refitted at a cost of $24 million for oil and gas exploration, and had been chartered by petroleum giant Chevron to survey for oil in New Zealand waters.

Siana Fitzjohn, Kailas Wild, Adrian Sanders, Genevieve Toop and Niamh O'Flynn were charged with being unlawfully on a vessel.

The were convicted and discharged in Auckland District Court today.