I was a couple miles off Esperanza Inlet about 10 years ago and saw a big one that I almost clobbered. At first I thought it was a piece of clear plastic and I turned the boat to retrieve it and when I approached you could see a fin on the surface. I read later how they will bask at the surface allowing birds to harvest parasites. There should be a photo on my laptop I'll post. It was big. At least 5 feet long. Later that season I heard in Tahsis that someone caught one over 200 pounds. Asking how they knew the exact weight I learnt that the skillful angler naturally had to kill it and it wasnt "caught" per se, but stuck with a halibut harpoon. How sporting is that? Most of it probably ended up in the garbage.
A side bar to this is to look for a book called Pacific Fishes of Canada. It lists and describes all these oddities encountered in these parts including the Ocean Sunfish.