Scuba divers know their air supply is their lifeline - but a diver has had his faith in one manufacturer shaken by the discovery the air compressor he bought for home fills was making carbon monoxide in excess of the breathing air quality standards and was unsafe.
"I was floored. I was breathing that air, my partner at the time was breathing it, and her 18-year-old son", said Tim Matheson.
A technical advisor to the NZ Underwater Association described the air compressor as "a loaded gun".
Mr Matheson's worst fears were realised after he shelled out $1600 for a professional air quality investigation on his Nardi Compressori Atlantic 100 electric dive compressor - a machine he’d already paid $5200 to buy new just before Christmas 2014.
The keen recreational diver told Fair Go he bought it for convenience but became concerned when the air tasted oily.
"You sort of got used to it," Mr Matheson said.
"Sometimes you just come up and you don't feel that well but whether it's that or the boat rocking around or whatever."
Mr Matheson made multiple attempts to return the dive compressor to the New Zealand agent for the Italian manufacturer, but the agent, Ben Vallings, determined that the customer was to blame.
"He's obviously caused a lot of these problems", Mr Vallings told Fair Go.
Mr Matheson admits that for some months he used a type of oil that was suitable for dive compressors but was not the oil recommended by the manufacturer.
He also installed an hour meter to the on/off switch to keep track of maintenance requirements.
Both voided his warranty and the agent says it made him believe the owner was at fault for the bad air.
Mr Vallings was unmoved by the report showing carbon monoxide was being made above the NZ Standard – this too he blamed on the customer.
"I think he's ruined the machine over the time and not been caring for it," he said.
The technical advisor to the NZ Underwater Association reviewed the report and shared its concerns.
"An electric compressor should not be producing carbon monoxide. Carbon monoxide is found from exhaust fumes and so there's a major, major problem with it," said the advisor, Steve Bishop.
"It's producing unbreathable air," he said.
Nardi strongly denies that and maintains the machines are safe, that thousands exist and no-one has died.
Nardi also disclosed that Mr Matheson's machine was made in 2014 under an old standard for carbon monoxide that permitted levels three times higher than today’s standard – and that the levels being produced by his machine were well below that original standard.
The company said all compressors manufactured after the update comply with the new standard and they offered to fix Mr Matheson's compressor a few months ago.
That offer - comprising of new oil and a filter - came after Mr Matheson's repeated insistence something was seriously wrong.
It was also made at least two years after the modifications to the standard were introduced.
The agent, Ben Vallings, denies liability but after Fair Go became involved he refunded the original sales price of the compressor to defend Nardi's reputation, and also paid Tim Matheson half the cost of the technical report, for a total settlement of $6000.
Mr Vallings told Fair Go he had sold about ten of the electric compressors, and had received no complaints about them.
He had not contacted the owners to check their air quality for carbon monoxide.
The NZ Underwater Association urged all divers to meet the commercial standards for air fills by taking three steps:
• Ordering a test of their compressors every 3 months they are in use, at a cost of less than $200.
• Becoming certified air fillers if they are doing home fills, at a similar one-off cost.
• Checking that the dive shops they use are up to date with those requirements.