The expertise of Northland's rescue helicopter team was needed to winch a sick fisherman from a boat 330km off the Taranaki coastline.
The Rescue Coordination Centre NZ called on the Northland helicopter about 5.30pm on Sunday after reports of a man suffering a heart attack on a fishing boat.
The crew flew to New Plymouth where they planned the mercy dash and waited for the 20 metre long-line fishing vessel to steam into range.
Chief pilot Pete Turnbull said the winch was one of an increasing number the service was called upon to do.
The rescue teams were completing up to 30 winches a year thanks to having two helicopters equipped for winching.
"We have developed some great expertise with St John and we have an amazingly capable helicopter," Mr Turnbull said.
The helicopter left land at 3.30am on Monday and reached the fishing boat at 4.50am.
Mr Turnbull used night-vision goggles during the winch exercise, which took seven minutes. St John intensive-care paramedic Mark Going was winched down to the stern deck by fellow paramedic Wally Mitchell.
Mr Going said a male in his 30s was suffering cardiac chest pains and was flown to Taranaki Hospital in a stable condition.