This is kind of an awkwardly phrased idea from my end, I know, but I'm not asking what a non-sexist society would look like; I'm asking you to look at moments/eras in your life in which sexism played a big role and to imagine that there had been no sexism towards you at all in those same crucial moments/eras.
Well, I have no idea how to become a ferry captain, but what's stopping you from being a writer? Maybe you only have five minutes of free time to spare right now, but all it takes to be a writer is to start writing!
That ferry incident is particularly gross because you were so young and enthusiastic; who the hell wants to be the person quashing that raw childhood joy?
Thats all it takes to be an average writer. If you want to be a damn fine writer (or any other kind of artist) you have to be able to focus and get into the zone. Its not something you can put down and pick up again, like knitting.
I'd be a writer...or possibly a ferry captain. I have an extremely vivid memory of my older cousin somehow getting permission for me to go onto the bridge of a ferry. I was enthralled, and said something about how I would love to do it some day. Well, you should have heard them guffaw. You'd think it was the funniest joke ever written. After the general additional comments about how dangerous it would be to have women captains, they came right out with. "Women can't be captains." " You could join the cleaning crew!", and, as a kindness " You cant be a captain, but lots of ladies work in the cafeteria." etc. I was 9 or 10 years old and felt absolutely ridiculous for saying something so stupid and absurd. I was also burning mad, because I could already drive a little boat with a small motor ( it was pre recreational boating licence days), and it didn't seem THAT much harder, but it instantly became another thing I wasn't fit to do.