Try this link
http://www.airtanker.com/quals.htm this should give you an idea of what you need in terms of experience in North America and Canada. According to this site only the Quebec Goverment operate the CL-215/ 415. I don't know about the rest of the world, I know the military operate (or did operate the CL-215) in Spain.
Try giving the search engines a good thrashing on the subject.
Hope this helps.
Regards
BTT
