Be it duck, merganzer or boat, they only spook for a minute. While rowing / floating in a pontoon, my buddy has yelle"this look ok?", chucked his rig at me....missed my boat and caught fish from under my pontoon on several occasions. It's now become a game to try and hook fish right next to the other guys boat.
If it's a big brown that reluctantly came out of hiding to feed early and 10 geese land right on him, he very well may be done until after dark but I don't think it really bothers a majority of the trouts.