The grieving family of an American tourist killed in a Queenstown skydiving accident have accused the aviation watchdog of inaction following the country's latest parachuting death. 

Tyler Nii, 27, died in January 2018 after a series of failures and gear malfunctions resulted in him and his tandem skydiving master crash landing into Lake Wakatipu. 

The skydiving company NZONE had no rescue boat on standby. Though boaties eventually pulled the instructor from the water alive, Nii submerged and his body was never recovered. 

A Transport Accident Investigation Commission (TAIC) report released in June last year found the company's water response emergency plan had not factored in the survival time in cold water and "increased likelihood that rescuers would arrive too late to save lives". 

Tyler Nii, pictured with his older brother, Kevin. Photo / Supplied 

TAIC recommended the Ministry of Transport work with the Civil Aviation Authority (CAA) and parachuting umbrella bodies "to mitigate risks of unintended water landings". 

Many in the industry believe this should be the mandatory provision of standby rescue vessels for all jumps over or near water. 

However, the CAA admits that one year on it is yet to begin work on the recommendation and any such project is likely to take up to 18 months to assess, then another two years to fully implement. 

In the meantime, British national Sarah-Jane Bayram has died in an unintended water landing off Muriwai Beach in March. 

Sarah-Jane Bayram, 43, was blown out to sea to her death after a mid-air collision over Muriwai Beach in March. Photo / Supplied 

She collided with another parachutist during a nine-person Skydive Auckland formation jump and was blown out to sea to her death. 

It later emerged there was no rescue boat on standby and she had raised concerns about strong off-shore winds before boarding the flight. 

Speaking from Southern California, Nii's older brother Kevin said it was upsetting to learn of another death and that CAA had failed to act on one of the key safety recommendations resulting from his brother's accident. 

"Here we are again ... it's really unfortunate. Even though there are changes that could prevent some of these things, it's not been done. It's tough to hear." 

Searchers look for skydiver Tyler Nii, who crash landed in Lake Wakatipu, in January 2018. Photo / ODT 

Kevin Nii has been highly critical of the investigations into his brother's death and lack of information shared with his family. 

He said the TAIC report had not provided adequate answers and the CAA's decision not to prosecute anyone meant there was no accountability. 

"Two parachute failures and a lifejacket failure. There was no rescue boat out there to save him. I just feel like there were multiple failures along the way and no real investigation. 

"They're saying nothing could have been done to prevent this. I guess what could have been done is you had a [rescue] boat there." 

He felt the New Zealand system was geared toward "no fault" and "no culpability", meaning there was little redress for when things went badly wrong. 

Tyler Nii, at right, with his brother Kevin and parents Nancy and Bob, before the tragedy. Photo / Supplied 

After losing Tyler, the family had been contacted by other families around the world who had also lost loved ones through adventure tourism accidents in New Zealand "and nothing happened". 

The Nii family are considering sending a dive team with a high-tech underwater drone to New Zealand to search for Tyler's body after police recently released GPS co-ordinates to the family about his last known location. 

But Kevin says this would be costly and he is realistic about the slim chances of finding his brother's remains after more than four years. 

"My parents would like to find his body. I don't feel different, I just don't think it's realistic anymore." 

Kevin said his family visited Queenstown shortly after the accident and went out on the water for a ceremony to help find closure. 

The coroner is yet to rule on Tyler's death, and despite the length of time since the accident, is yet to decide whether to hold a formal inquest. Officially, Tyler remains a "missing person" who police have been unable to locate. 

Meanwhile, the family are still hurting and Kevin said he missed his brother every day. 

"I've had two kids that my brother never met. It's mostly just feeling all the things that he should have been a part of and he hasn't been. That's the hardest thing. 

"We try to keep talking about him and keep him alive in spirit but his absence is definitely felt. 

"In so many ways he just left on vacation and we never saw him again." 

Tyler Nii, a tennis coach from Southern California, was on vacation in New Zealand when he died in a skydiving accident in Queenstown. Photo / Supplied 

A CAA spokeswoman said the agency had already made changes following the TAIC recommendations, which included improvements to the accident and incident reporting system. 

An "issue assessment and policy development" process was planned in response to the water landing recommendation to evaluate options, followed by a more rigorous policy investigation process which could take several years. 

"This particular issue is currently pending assessment and work has not yet started on it. It is one of a large number of pending issue assessments, and work will commence when capacity becomes available, and according to its priority within the CAA's wider policy work programme." 

An experienced skydiver, who asked not to be named, said it was a no brainer to make rescue boats mandatory when parachutists were jumping near bodies of water. 

"They need to put some resources into it and prioritise it before there's another death. How many does it take?"