Coroner calls for ban on breathing device after Mana Island drowning
Wednesday 9 September 2026 · 2 outlets · 2 reports · updated 
A coroner has recommended banning the importation of a specific surface supplied breathing apparatus into New Zealand. The call follows the 2023 death of Shengwei Cao, a Lower Hutt man who drowned while diving near Mana Island using the device purchased online.
Key facts
4 facts
- Shengwei Cao, 58, drowned accidentally off Mana Island on 5 March 2023
- The Wolach 919 Surface Supplied Breathing Unit is recommended for an import ban
- The device was tested by the Police National Dive Squad and found to have inconsistent air pressure
- Cao had no formal scuba diving training
The full story
1 min read · 4 outlets
A coroner has recommended that the Wolach 919 Surface Supplied Breathing Unit be banned from importation into New Zealand. This recommendation follows the accidental drowning of 58-year-old Lower Hutt painter Shengwei Cao off Mana Island on 5 March 2023.
Police National Dive Squad testing found the device was dangerous because it failed to provide constant supply pressure. The compressor only activated after a pressure drop, making it difficult to breathe at depths between 4.5 and 5 metres. This could cause a diver to feel they are running out of air, potentially leading to panic and carbon dioxide build-up.
Cao, an experienced free diver with no scuba training, had purchased the 'hookah' style system online to dive deeper. On the day of his death, he reported the device was not working and that he felt seasick before returning to the water. He was eventually found in approximately five metres of water, still attached to a buoy with the pump running, but with the mouthpiece moved to the side of his head.
Forensic pathologist Dr Judy Melinek determined the cause of death was drowning. Contributing factors included complications from decompression, an air embolism, and cardiovascular disease. The coroner also noted that Cao was diving without a depth gauge or dive computer and was wearing heavy, non-releasable weights.
How it developed
- Wed 9 Sep, 6:00amThe Ministry of Business, Innovation and Employment stated they require more information before determining if regulatory intervention is warranted.
Where reports differ
- Reports vary on the specific number of companions present, with one stating five companions were scuba diving nearby and another mentioning a friend named Chen Koo
Compiled from reports by The Post, Stuff, NZ Herald and 1News.