Glasgow men Craig Currie, 30, Thomas Douglas, 36, William Carty, 47, and Stephen Carty, 42, lost their lives in March 2009 after getting into difficulties on a nighttime return journey across the loch, to their camp site, in thick fog.
The inquiry at Oban Sheriff Court heard a phonecall made by their friend, Edward Colquhoun, who had stayed at the campsite, near Kilchurn Castle, while his friends made the boat crossing to the Tight Line pub.
He dialled 999 when he heard them cry for help in the early hours of the morning.
Although the detail of the words was hard to decipher, because of heavy interference on the line, there was no doubting the haunting shouts from the friends on the boat.
A cry of "help" could be heard. On numerous occasions Mr Colquhoun, 40, was heard frantically shouting to his friends: "I cannae hear you."
When he took the witness stand Mr Colquhoun said Stephen Carty was his brother-in-law and he had been friends with all the men for years and had gone on many fishing trips with them.
He said normally they would only use the boat during the day, and would walk or take a car if they went to the pub at night.
Mr Colquhoun said the four men had gone to the pub while he kept an eye on the campsite. He said: "Stephen phoned me about 12 o'clock, to tell me they would be back about 1am. Stephen was in the pub playing pool, he asked me to stoke the fire and put petrol in the lantern."
Mr Colquhoun said that, after falling asleep: "The next thing I heard was a scream. I woke up and went to my phone and I had three missed phone calls. The last number on it was Stephen's.
"I tried to phone him back, but it went on to the answer machine. That's when I went to look for them."
He said: "I shouted to the water and heard cries for help. Once I realised they were in trouble I was trying to light petrol round about to give a light in. I heard Craig – he was shouting 'dial 999 – get help'."
He continued: "I was shouting, 'are you all right?' I couldn't hear their voices."
Asked by Sheriff Douglas Small if either of the men who were shouting had said what the trouble was, Mr Colquhoun said: "No."
Asked by Procurator fiscal Craig Harris how long the shouting back and forth went on, he added: "It seemed like forever."
Mr Colquhoun had earlier told the court that the men had enjoyed a final supper round their camp fire, before his friends boarded the boat.
The court was shown bottles and cans that were found at the site.
Mr Colquhoun said they had all had something to drink but were not drunk.
Admitting that he is a former drug user, Mr Colquhoun said he took prescription methadone at 9am on the day they drove to Loch Awe. He said he did not feel any adverse effects from the methadone, or after a drink later that evening.
The inquiry continues.
Desperate calls in the dark to help his friends
THE court heard the phone calls Edward Colquhoun made to the emergency services as he tried to work out what had happened to his four companions.
Edward Colquhoun (to his friends): "I am dialling 999" and "I am on to the police – can you hear me."
Responding to the Fire Brigade operator: "They are on a boat"
Fire Control: "And they have fallen out the boat?"
Edward Colquhoun: "I don't know."
Edward Colquhoun (to his friends) : "I can hear you."
Edward Colquhoun (to the police) "I think they are OK officer."
Edward Colquhoun (to his friends): "Can you hear me, can you hear me?"
Edward Colquhoun (to the police): "I cannae see them, I can hear them, but I don't know where they are."