The idea was first proposed by the New Zealand Underwater Association. It seemed a fitting end for a ship that had spent its time protecting the marine environment.

It was towed north with a patched hull on 2 December 1987. Ten days later, a crowd of well-wishers looked on as it was given a traditional Māori burial. Now home to a complex ecosystem, the Rainbow Warrior has become a popular dive destination. The local Māori community maintains its guardianship and conservation. In a few short years, the Rainbow Warrior became an integral part of the environment it helped protect.

http://en.wikipedia.org/wiki/Matauri_Bay