TWO men clinging to their overturned boat near Lady Musgrave Island would have been floating for days if it wasn't for their emergency beacon - and it wasn't the first time they had used it.

The men, both 32, were on a fishing trip and had anchored up next to Lady Musgrave Island to sleep.

In the early hours of yesterday morning they woke to water pouring into their six-metre boat. They could not find their lifejackets and only had time to grab their emergency beacon before their boat sank.

They had to be rescued by the RACQ Capricornia Rescue Helicopter Service two nautical miles north of Lady Musgrave Island and taken to Rockhampton Base Hospital with minor cuts and bruises.

Aircrewman Garth Snaidero said if they didn't grab the beacon they would have been "goners".

"The vessel had overturned when we got there at first light," he said.

"One man was sitting on the upturned hull and the other was hanging on to the side of the boat.

"Without any lifejackets they were lucky, very lucky and it wasn't their first time.

"They were rescued in 2008 when another boat of theirs sunk up near Townsville."

Mr Snaidero said the men weren't due back for two days - and so "we wouldn't know where to start looking after they had been floating around for that long".