RCMP say the pilot with NorthWright Airways was on a regular flight from Inuvik to Aklavik noticed the call for help spelled out on a cabin roof along the Mackenzie River.
He also reported that he saw seven people waving for attention.
The group had been missing for several days, and police say the search was difficult because no one knew where the boaters were headed.
The pilot radioed the co-ordinates of the cabin to authorities and the RCMP later found everyone at the cabin safe and sound.
NorthWright Airways operations manager David James says the group initially caught the pilot's attention by reflecting sunlight with a mirror.