Maritime NZ is asking recreational sailors not to go into BoP waters for fear of dragging oil into cleaner areas.

Thieves have made off with anchors from a boom protecting an estuary from the Rena oil spill.

The crippled MV Rena could be a blot on the Bay of Plenty coastline well into next year if bad weather doesn't smash it apart and the cost of the clean-up and long salvage operation could stretch to $100 million.

Authorities assisting with wildlife recovery are being inundated with oiled little blue penguins. It is the middle of breeding season for the nocturnal birds who get covered in the thick tar-like oil while crossing rocks to return to their burrows.