Some newly installed safety buoys in the Marlborough Sounds have disappeared.
The Marlborough Harbour Master, Captain Alex van Wijngaarden, has condemned the theft as irresponsible.
Harbour staff have spent the past few days installing buoys that advise the five-knot speed limit in the Marlborough Sounds, at locations where there have been problems with vessels travelling too fast and too close to the shore.
Within 24 hours, one set of buoys placed in Double Cove disappeared.
Captain van Wijngaarden said it was an irresponsible act that put public safety at risk.
He said police had been informed