Days after a wombat was rescued from a lake in central Tasmania, another tale has emerged of an angler giving a submerged marsupial a helping hand.

Nobby Clark said he plucked an echidna from the chilly waters of nearby Lake Echo when he spotted it swimming about 150 metres from shore, and heading further out.

Last week, a wombat swimming 250 metres out in Wood Lake was scooped out of the water by two fishermen.

Mr Clark, who describes himself as a passionate recreational fisherman, said he had been fly fishing for about two hours when he spotted ripples coming towards him.

"I thought it was a platypus heading towards me but it turned out to be an echidna," he said.

"His head would go under water and then his little periscope would come up for a moment and have a breath and head out a few more paddles.

"He was swimming pretty hard; I think he was trying to figure out how he was going to get home.

"The direction he was heading was certainly not a good option for him."

Echidnas are known to swim, but it is the first time Mr Clark has seen one out in a lake.

"We see some absolutely wonderful things when we are experiencing some of the great outdoors of Tasmania, and certainly I wouldn't go as far as saying it was anything out of the ordinary, but it certainly raises some eyebrows when you see these things offshore," he said.

Mr Clark was able to safely take the echidna back to shore and place it on a warm log to "thaw out".

"He was quite exhausted when I got to him, so I think he was pretty happy to have a ride home," he said.

"He just sat there in the sun for a good half an hour, I could see him still sitting there defrosting and he went on his way."

More echidnas spotted taking a dip

It is the latest in a series of similar reports, with one seen swimming last month at Friendly Beaches on Tasmania's east coast.

Echidna expert and Associate Professor at the University of Tasmania Stewart Nicol said a combination of good recent survival rates for the young and phone camera proliferation may explain while they are being reported.

"They can paddle along quite happily without too much effort for quite a long time," he said.

Last year, an echidna was spotted two kilometres out in Darwin Harbour.

"Not only was it swimming quite a distance but it had managed to evade all the crocodiles."

Associate Professor Nicol said it was unlikely the Lake Echo creature was just out exercising on a sunny day, but the "rescue" was probably not unappreciated.

"One of many interesting things about echidnas is they don't waste any effort so it wasn't out for some exercise," he said.

"It presumably was trying to get somewhere... perhaps it thought it was a platypus.

"It's perfectly reasonable to pick them up and bring them back to shore but I wouldn't be actually risking your safety to do it."

Scientists are yet to delve into swimming endurance capabilities.

"It's hard to tell unless we are watching them for a long while, "I don't think anyone has had a long series of observations of an animal doing this."

Asked if that could be an opening for a PhD student he replied: "That's an idea to float."