"Some organisations, 61 out of 79, reported that the cumulative effect of repeated recommendations may aid the uptake of coronial recommendations.
"However, coroners themselves felt that their repeated recommendations are falling on deaf ears and are not being implemented."
Of the 607 findings looked at, 1644 preventive recommendations had been sent to 309 organisations or individuals since 2007, when the New Zealand Coroners Act came into force.
Of those recommendations, the study found that 324 identical repeated recommendations had been made - many of those in cases of drowning and sudden infant deaths.
Chief coroner and District Court Judge Neil MacLean welcomed the findings and said it showed it should be mandatory for people or organisations who had received recommendations to at least respond.
"We're not asking for mandatory implementations - that there's an obligation for the Government to do something.
"But we're asking that when we send you a recommendation, could you please respond to say whether you think it's good or rubbish.
"There have been occasions in the past where coroners have made a recommendation to an organisation who say: 'We never knew this was coming, why weren't we told about it?' That's a very valid criticism."
In 2011, Bishop Thompson, 17, died while jetskiing with friends on Lake Okareka, in Rotorua.
The teen had fallen off his jetski and was run over by a friend on a jetski who had not seen him.
Two years earlier, coroner Wallace Bain had made recommendations including that anyone operating a powered boat or jetski should have a licence.
The recommendation had come following the tragic death of 9-year-old Genevieve Lewis, who had been run over by a boat while waterskiing.
Last night Bishop's uncle, Mana Witoko, supported the call to make coroners' recommendations mandatory.
"The message doesn't get across until someone dies. But how many people need to die?"
Judge MacLean said it had become almost a normal thing for coroners to think that they had to keep pushing out the same recommendations for them to finally stick.
And when another accident or death occurred, where a recommendation's implementation could have prevented it, it was heartbreaking.
"I think it breaks coroners' hearts to think: 'Gosh, what's the point of making recommendations if they just disappear and we never hear what's happened until next time?'"
The issues
• High number of repeated and identical recommendations, particularly in drowning and sudden infant deaths.
• Poor information-sharing systems.
• Shortage of available outside expertise.
• 72 out of 309 recommendations too vague - did not specify any particular organisation.
