A 67-year-old man has been rescued by police after trying to sail from the Melbourne suburb of Williamstown to Tasmania.

Key points: Rescue crews were unable to reach the man due to dangerous and shallow waters

Rescue crews were unable to reach the man due to dangerous and shallow waters The police Air Wing could not winch him from the deck because of a swinging mast, and had to rescue him from the water

The police Air Wing could not winch him from the deck because of a swinging mast, and had to rescue him from the water The man was taken to hospital for observation

The Tasmanian man was trying to sail home on Wednesday when problems with his yacht forced him to turn back to Melbourne.

He attempted to enter Port Phillip but ran aground at Corsair Rock near Portsea about 7:30pm.

The man put out a mayday call on his radio, but dangerous weather conditions and shallow water meant the Coast Guard and Southern Peninsula Rescue could not reach him.

The yacht could not be pulled ashore and was found in the shallows of the beach Thursday morning. ( ABC News )

The police Air Wing was called in but the yacht's swinging mast made it unsafe for the man to be winched from the deck.

An Air Wing crewman was lowered into the water and told the man to jump into the ocean where he was winched to safety.

"The rescue itself was quite hazardous as a night winch for Polair [the Victoria Police Air Wing] is a difficult circumstance by any stretch," Acting Sergeant Rob Hiep of the Water Police said.

The man was taken to hospital for observation with mild hypothermia.

Police implore boaters to 'stay home'

Acting Sergeant Hiep said whether the man's proposed interstate sailing trip was essential travel under the current coronavirus restrictions would likely form part of investigations into the rescue.

"The Chief Health Officer has stated that there are only four reasons to be out and boating is not one of them," he said.

"From here we're continuing to conduct investigations as to why and under what circumstances the male was actually conducting this voyage and we'll have an outcome shortly."

He said Water Police would be patrolling Victorian waters over the Easter weekend.

"We implore everyone to adhere to the guidelines that have been set down the the Chief Health Officer and just stay home," he said.