Everyone who operates a boat on any body of water in Canada needs to understand the Collision Regulations (Col Regs). These are effectively the rules of the road and paint a clear picture of who has the right of way when it comes to different kinds of boats/ships engaged in different activities.
Rule 18 tells us the pecking order from top to bottom:
Vessel not under command (damaged, loss of steering or power)
Vessel restricted in her ability to manoeuver (restricted by draft, tow, dredging operations)
Vessel engaged in fishing (Commercial)
Vessel under sail
Vessel under power
Here are the Col Regs:
http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._1416/page-4.htmlLook at Rule 3 for definitions, specifically 3d and 3f
If you are broken down and unable to navigate you need to use your VHF radio and contact either Vessel traffic or Coast Guard Radio so that others operating on the river can provide assistance or at least avoid running you over assuming you are simply anchored while fishing.
Someone mentioned that a vessel coming down river has the right of way and that by itself is false. If it is a tug engaged in towing operations, then yes, absolutely they have the right of way. Tugs in the river are typically are on a short tow line which limits their ability to change course. As hard as they try, that tow will keep making way and will drag the tugboat with it. Have a look at this accident where a barge overran the tug.
https://www.youtube.com/watch?v=QEfUblSDzww