Long was found to have a blood alcohol level of 245mg per 100ml, almost five times the legal blood alcohol limit for a NZ driver 20 years or older.
Pathologist Sage said collapse with sudden death or total immersion indistinguishable from drowning was a well recognised risk of the use of hot tubs.
This was particularly so in the context of concurrent alcohol intoxication and underlying cardiovascular disease, which Long had.
In Japan and Korea where hot tub use was traditional, many thousands of deaths have been reported and investigated, he said.
However, Sage noted there was some contention in literature from the United States as to whether or not treated hypertension was also a risk for cardiovascular collapse in these circumstances.
Coroner Tutton said some spa pool suppliers advertise that spa pools may help lower blood pressure.
"The extent to which the public is aware of the risks identified...is unknown," Tutton said.
Tutton said publication of the risks could help reduce the chances of someone else dying in the same way as Long did.