pseudo, you may be correct, as i know of no written law in regards to passing waders. Although it more than likely is a written law in the Canadian Shipping Act or Canadian Shipping Regulations. That would make it federal law and a criminal offence...... i'll look into it sometime, but not soon.
however, it is curtesy and tradition to give the active wading fisherman his water. It has a lot to do with the fact he was there first so what gives you the right morally or legally to float through, on top of, or too close to his water. others are right on this if you where also wading would you hop into the river and wade the same distance from that angler?
i have also guided in the past and still float alot. i also wade alot. so i know sometimes rowers are inexperienced or inattentive or both and mistakenly they come to close for comfort invading the waders "personsal fishing space". a simple i'm sorry works. but if the captain is directing or allowing his sports to continue fishing to the waders bank he is an ignornant or he continues to do so because there is no written law preventing him or his from fishing which ever water they please no matter if it is already occupied.
when people loose curtesy and the "unwritten rule" it forces written law upon us.
other than that if a cast happened to go way further than a wader expected it to he couldn't be convicted of assault or anything in written law either. remember there was no intent to hit the people on the boat, it just happens sometimes when you suddenly have get timing or a good double haul and you didn't even see the boat, just like they didn't see you......