Skils.ca probably offer incident management with their guiding courses.
The best incident management courses I have done in dynamic water, have been with Body Boat Blade on Orcas Island (actually in Deception Pass, so easier to get to). Across the border unfortunately and USD, but well worth any training you do with them. I also did the same course with them at a Lumpy Waters symposium in Oregon. This is a really fun weekend with lots to choose from. Contact me personally if you would like more information.
Our trip leader course offers incident management in a group dynamic in a more general way