Tour guide Nick Templeman summed the experience up: 'The most insane thing that has ever happened to me'.
Mr Templeman described what is happening in the video here: 'We came on to the scene near Powell river to watch about a dozen transient killer whales. They were lazily swimming when all of a sudden they went into hunting mode.
We then saw the seal and saw him being pulled under water a few times (transients like to play with their food) we saw the seal see our boat and it beelined it for us and hopped onto the swim grid.
The orcas soon followed and circled the boat a few times and then moved off. The seal jumped off the swim grid a few times as it was also scared of us. When it did, the orcas would come back looking for it.
Eventually the seal stayed on and for about 45 mins the orcas circled and tried to come up from underneath'.
Footage courtesy of Campbell River Whale & Bear Excursions.