bears

[Desert Fox]

Hi,
I often meet bears when I do some land nav.They are always escaping. A good thing with bears is that it simulates the enemy, and that makes me very cautious, particulary in dense (< 20m line of sight) .When I am in a very dense place where a bear can be surprised(which is dangerous), I say some words loud.
I would be interested to know some way to defend against bears.Here in Canada pepper spray is not permitted, nor firearms (except during hunting season, and with a license).
I would like to know if it is realistic to defend myself with a knive,with proper technique, oubviously.If the blade is pointed foward the force of the collision will just throw the knife away.
I'm thinking about some ''reaction technique": right arm with the knife protected behind, left arm protecting the face.The knife against the side/back of the bear.

I though about some powder CAT A-B fire extinguisher.


Thank you.