The humpback surfaced as stunned kayakers Alan and Kirsty Moore paddled off the isle of Kerrera, which overlooks Oban, on Wednesday.
As news of the visitor spread, Oban marine expert Shane Wasik, captured the inquisitive mammal on camera as it later swam up to a local boat.
For Mr and Mrs Moore it was a once-in-a-lifetime experience, as the marine giant joined them for an idyllic 15 minutes in inshore waters, miles away from its usual deep sea haunts.
But the off-duty police officers made a fast getaway as the creature hit Mr Moore’s kayak twice with its tail.
The couple were paddling to town from Kerrera, a stone’s throw away from Oban Bay, when they encountered the whale.
Mr Moore, 45, said: “We saw the whale come up, about 150 yards away and it followed us, then it started getting closer and closer and came right up beside us. It was such a nice day, there was just me, Kirsty and the whale.”
However, the massive creature then ventured underwater and its tail clipped Mr Moore’s kayak.
He said: “Kirsty was a lot calmer than I was, but it was my kayak that it hit with its tail. I said, we need to go now.
“It wasn’t aggressive, it just seemed quite inquisitive, but it was massive, really, really big, its tail was the size of my kayak.”
He added: “There was a rock face opposite us, so we couldn’t go ashore, we just paddled to the side and held on to the rocks until it left.”
The couple have only recently bought their kayaks and were only on their seventh or eighth paddling expedition.
Mrs Moore, 37, said: “We were in Mauritious in September and we saw humpback whales in the distance, then we see them close up here, pretty much in our own garden. It was incredible to see, although we never realised at the time it was a humpback and how rare it is to see one here. We probably won’t see it again in our kayaks. It makes you realise how tiny you are compared to these, we couldn’t grasp the size of it.”
When marine biologist Shane Wasik, boss of Basking Shark Scotland, heard there was a humpback in the area he boarded a boat to look for it.
He captured it on camera as it swam beside a local boat crew and then used a go pro camera, over the side of his boat, to take an underwater picture.
Mr Wasik, who runs tourist trips to the Hebrides, to see basking sharks and other marine life, said: “I don’t think there has ever been a humpback whale in Oban before. You could be here for 100 years and never see that, to see it is rare and a bit of a privilege.”