I assume that since you are in BC you have found a Pacific Giant Octo, and I don't have any experience with that particular type of octopus.
That being said, I found common reef octopus in the Carribean many times and often succeeded in interacting with them. I found that if I found one already out of its den it was easier to interact with them. This generally only happened at night when they were out hunting, but if it wasn't swimming and I slowly put my hand down right beside it and waited, it would almost always touch my hand, after a long wait during which it would just look at me.
If the octos were in their den, it was harder to engage them, but I still found that if I could see the octo or part of it and put my hand beside it, it would still often touch it. Patience is key as this often involved waiting immobile for a long time. With experience, I could usually tell when it was going to 'make a move' because it would turn one of its arms tentacle side up.
I always dived with a flourescent orange inflatable surface marker buoy and the octopuses often seemed to be interested in this item and if I put it down in front of them and waited, they would often try to grab it. I have read that octopuses are attracted to bright, shiny things, so you might try taking something similar with you to attract it. One good book I read about octos was "Octopus and Squid: the Soft Intelligence", by Jacques Cousteau.
All this being said, I would proceed with extreme cautioun when dealing with a Pacific Giant. The carribean reef octos I was dealing with were perhaps a foot or so in length and their strength was ASTOUNDING. The first time I put my hand down beside one and waited for it to touch me I thought it would make a tentative move, if it did anything at all, and I had to wait a LONG time, perhaps 5 minutes. When it did touch me, it went from nothing to suddenly GRABBING my arm so forcefully my whole body was pulled. It startled me quite badly, and I found the same type of strong grabbing, pulling behaviour with several of the other octos, where they played tug of war with my surface marker buoy, and if I hadn't been attached to the buoy by a string I might've lost. These guys are STRONG!!
An octo would never intentionally harm you but if a Carribean one-footer is that strong, I can't imagine the strength of a pacific giant, and they are very curious. Make sure you are prepared for various situations -- what if it pulls out my reg? or pulls off my mask? etc.
Good luck with your quest -- I think the octo is the most fascinating, beautiful animal on the planet and I fully understand your desire to "make friends". I also commend you on not wanting to feed it. I believe however well-intentioned, or however occasional, feeding wild animals changes their behaviour and is not good for them.
Let us know how it goes!
