I mean, what about feeding them a few snacks - can they be bought off?
Seems to me a daring sailor might ought to find the answers to these questions ..
What sailors will admit they do but not tell anyone: Dump a bit of diesel or petrol in the water around the boat to scare away the orcas.
There are also some new gadgets available to make high pitched sounds that humans can't hear but scare away orcas (and dolphins, unfortunately) but no idea if they work well.
Pumping bilge water into the sea makes them go away real quick. It's obviously illegal, but frequently done.
Everything in the ocean is getting blasted by our human sound. Shipping, sonar, drilling - none of this ever stops and I would not be surprised if the Orcas have had enough.
That's likely why they're attacking boats in the first place.