The "old school" way to go about things is dock walking and talking to captains. And in my opinion is a great way to start The other suggestion is to call or email and see what kind of response you get. If you were local I would be able to direct you a bit better but Im on the opposite end of the lake.
Feel free to use my club's data base to reach out to some local captains https://lakeontariocharterboatassociation.com/