But one light aircraft, carrying the registration VH-PXD, did not make it across  Bass Strait.

Investigators are still piecing together the circumstances of what happened a week ago when a 1967 Piper PA-28 Cherokee plummeted into the ocean just off the Victorian surf coast without making a distress call.

On board were four friends, Daniel Flinn, Donald Hately, Ian Chamberlain and Dianne Bradley, a group of experienced aviation lovers in their 50s and 60s from Melbourne's south-east. They all died when the plane hit the water.

Among those feeling the loss are the pilots and passengers of other planes who were also due to make the short trip down to rugged King Island, a windswept place just to the north of Tasmania best known for its high-quality cheese, lobster and beef.

The loosely organised group, co-ordinated by a senior member of the Royal Victorian Aero Club, planned the flyaway to attend the Festival of King Island and the final day of horse racing for the summer.

"King Island is an easy 1½ hours each way in a Warrior [plane]," the invite read.

"Fly down to Cape Otway - a scenic run along the Great Ocean Road - to minimise the water crossing."

Some cancelled the trip after hearing about the crash. Others pressed on unaware of what had happened to the plane, which was owned by Mr Chamberlain and recognisable for its red and white livery.

One convoy member flew on about 30 minutes behind the Cherokee in his own Piper Arrow, oblivious of what had unfolded ahead and apparently untroubled by the poor weather that may have played a part in the crash.

"It does affect them, there were people who were going down on Saturday that pulled the pin," said Royal Victorian Aero Club president Stuart Rushton, who was not part of the group.

"There were others who decided to put their passengers on King Island Airlines and come back."

As the tight-knit small plane community comes to grips with the crash, bad conditions have stalled dive crews from accessing the sunken wreckage which sits on the bottom of the ocean floor about 2km off Collendina Beach in Ocean Grove.

Water Police have loaded a barge at Williamstown and hope to begin the salvage on Sunday.

Police are preparing a report for the coroner, while the Australian Transport Safety Bureau investigates what may have led to the crash.

Many are asking why a plane carrying three pilots would fly into what appeared to be deteriorating weather conditions.

Witnesses on the day reported bad weather, including pouring rain and low visibility, factors which the ATSB will investigate as well as the pilot's training and maintenance records.

Peter Lewry was fishing off Swan Bay, near Queenscliff, when he saw the plane flying low, maybe even as low as 100 metres above the ocean, and heading straight towards bad weather.

"It didn't sound like the plane was in any trouble at all, but they were flying into some really heavy weather, they were heading right into it; terrible sky and lots and lots of heavy rain," Mr Lewry said.

Aviation expert Neil Hansford, chair of Strategic Aviation Solutions, said the most common cause of plane crashes is pilot error.

"Certainly disorientation in cloud is a major contributor," he said.

"Having all that fluffy white stuff around, you can't identify things around you and the sea makes it more complicated; there's no roads or road maps."

The condition, called spatial disorientation, can happen to even the most experienced pilots.

According to the Civil Aviation Safety Authority, spatial disorientation occurs when "your senses are telling you something that isn't true - typically that you are flying straight and level when in fact you are in a spiral dive".

Who was at the controls of the Piper Cherokee when it hit the water has not been made public.

Mr Handford said a big question that needs answering is whether the pilot was trained to fly with instruments such as GPS and not solely by visual cues.

"If he's instrument rated, you feed into the GPS, no different than GPS navigation in your car," he said.

"It doesn't matter if you're flying in cloud or not."

"If he wasn't flying on instruments and he was doing VFR [visual flight rules] and he was in cloud, he'll obviously try to get out of the cloud and you've got to get below it."

In an odd coincidence, the ATSB has confirmed that the same plane, manufactured in 1967, was involved in another crash more than 25 years ago.

On a windy day in October 1988, according to an investigation report, the pilot made a rough landing after a faster-than-normal approach to the runway at Melton Airport.

There were no serious injuries in that crash but the plane, registered VH-PXD, did sustain a broken wheel assembly which allowed the propeller to strike the ground.

The ATSB says it will release the initial findings of its latest investigation in the coming months, perhaps providing some answers to families and friends.

In the meantime, a small tribute has been set up at the Point Lonsdale lighthouse:

"For a second you were flying like you all loved to do," it begins.

"Now you'll fly forever in skies of amazing blue."

Tom Cowie and Tammy Mills