A coroner wants tourism operators offering snorkelling and dolphin encounters to carry oxygen on their vessels and warn participants of the potential risk involved, following the death of an American tourist in the Marlborough Sounds.
Emily Harper, 27, died in October 2009, while she was snorkelling with dolphins, near Picton, with her fiancé and his mother and brother.
Coroner Christopher Devonport found Ms Harper died after suffering a likely cardiac arrhythmia while she was swimming, which caused her to lose consciousness.
She was found face-down in the water and attempts to revive her failed after she was brought on board the Dolphin Watch Ecotour vessel.
She was pronounced dead shortly after the vessel arrived at Waikawa, where waiting ambulance staff also tried to resuscitate her.
Ms Harper had failed to disclose she was bipolar and was taking four kinds of medication on a group declaration form required to be filled out before the trip.
Mr Devonport says while it's up to individuals to make a judgment on whether they are able to participate, they should be told that snorkelling can be physically demanding.
It could put those with existing medical conditions at greater risk of cardiac arrest or death, he said.
He has recommended that commercial snorkelling operators give such advice to participants and that they be given individual waiver forms, rather than group forms, to fill out.
Mr Devonport also wants vessels to carry appropriately sized oxygen cylinders and masks, which are checked daily and kept in good condition.
He's also recommended that maritime regulations require that, unless it can be shown that it cannot be safety stored, an automatic external defibrillator be carried.
NZN