HI ex-navy - I'm curious as to how your dad did it - did he just stop by himself, or did he get involved with a group? I read a lot about people who just quit. It wasn't within my power to do that, but I have lots of respect for people who do. Glad you're talking to him about your issues. The more secrets we keep from others the more harm we seem to do ourselves. Seems to me that people who successfully quit have one thing in common - they make quitting alcohol an absolute, either an absolute personal standard, or they recognise their alcoholism as an absolute beyond their control. And then they quit - either "forever", or if they can't do that, just for today.
Good to see you here, and I hope your search for a solution bear fruit.