A 70-year-old solo sailor has been rescued from his yacht 20km off the Wairarapa coast after being struck on the head by the boom.
The man, who was sailing from Auckland to Picton, made a mayday call shortly before 11am.
The Rescue Coordination Centre says the fishing vessel Otakou responded immediately and brought the sailor on board.
The Westpac Rescue helicopter from Wellington later winched the injured man aboard and flew him to Wellington Hospital.
A police officer and crew from the Otakou later boarded the yacht and are sailing her to rendezvous with the police launch Lady Elizabeth IV, which will tow the vessel to Wellington.