Mr Cathie said he regularly received emails from scientists and researchers from around the world who had been inspired by his father's work.
"I believe he was a genius. Many other people do so too...and his legacy lives on."
Captain Cathie grew up in Onehunga and Otahuhu. He worked for years as an airline pilot for the then National Airways Corporation - New Zealand's domestic airline which later merged into national carrier, Air New Zealand.
However a chance encounter in 1952 changed his life forever. He was among a group of co-pilots who saw what he described as a UFO hovering over the Manukau Harbour.
The captain believed the manoeuvres it had carried out that evening could not have been made by any man-made machine and decided to investigate further.
In later years he came up with complicated mathematical theories that he believed could help predict how UFOs operate and when certain nuclear-based events on earth would take place.
He wrote a total of six books over the years, including Harmonic 33, The Energy Grid and The Harmonic Conquest of Space, which also became well known internationally.
At his funeral yesterday, it was acknowledged that Captain Cathie had taken a lot of flak from skeptics over the years. He also had to deal with people who had seen what he had seen, but were not brave enough to talk openly about it.
Despite that, he was determined to do the work he was passionate about, son Mark said.
"Nearly every pilot talked about [seeing objects in the sky]...but in hushed tones. Nobody wanted to talk about the elephant in the room.
"He left a very big footprint, for a quiet man. Dad was a quiet soul, a deep thinker."
Captain Cathie's wife Wendy, whom he met while working for the NAC airline - where she was an air hostess - talked about a sensitive partner who wrote poems for her.
"We would always leave a note in each other's little cupboards. Believe it or not we were great dancers. Everyone was always getting us to start the dancing."
Captain Cathie is survived by wife Wendy and sons Stephen and Mark.
Captain Cathie's theory:
Using complicated mathematical calculations, Captain Cathie formed a theory dubbed the World Energy Grid System.
It is based on the idea that a grid-like energy pattern covers the earth and which has the power to control or cause nuclear-based events such as a nuclear explosion or bomb.
According to him, this same energy grid is also the power source for UFOs that regularly appear and are seen by people all around the world.
In 1994, Captain Cathie described his calculations - the main one dubbed the "harmonic equation" - to Nexus Magazine.
"I came to the conclusion that the speed of light, mass and gravity acceleration values must have some connection with the grid structure in order to explain the extraordinary manoeuvres carried out by the strange craft."
In later years Captain Cathie said he came to find that his energy grid system was a concept that was already widely understood by various scientists and international researchers.
He told the magazine: "It became obvious that the system had many military applications and that political advantage could be gained by those with secret knowledge of this nature."
